Tesi: "Flora plant"

1

Stonehouse, Amanda L. "The flora and plant communities of Botany Glen". Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1266033.

Testo completo

Abstract (sommario):

Botany Glen, The James S. Wilson Memorial Sanctuary, is an 18 hectare (45 acre) forested tract located in Grant County, Indiana, adjacent to the Mississinewa River. Botany Glen is an important natural area in east central Indiana due to its relatively small size and high diversity.The flora documents 331 species and varieties of vascular plants representing 241 genera and 90 families; 158 species are recorded for the first time in Grant County. Of the 331 species listed, 67 (or 20%) are exotic. Most of these exotics have failed to penetrate the interior of the forest.Permanent monitoring plots were established in dry upland forest, floodplain forest and secondary successional forest. Data were collected from overstory, understory and herbaceous plant layers in these plots. Analysis of these data and information from the floristic inventory were utilized to describe the structure and composition of three primary plant communities. Baseline data and procedures were established for future study of this property.
Department of Biology

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Wasley, Jane. "The effect of climate change on Antarctic terrestrial flora". School of Biological Sciences - Faculty of Science, 2004. http://ro.uow.edu.au/theses/275.

Testo completo

Abstract (sommario):

Climate change is expected to affect the high latitudes first and most severely, rendering Antarctica one of the most significant baseline environments for the study of global climate change. The indirect effects of climate warming, including changes to the availability of key environmental resources, such as water and nutrients, are likely to have a greater impact upon Antarctic terrestrial ecosystems than the effects of fluctuations in temperature alone. Water availability is the focus in this thesis for two main reasons; firstly, there is a wealth of evidence to suggest water is currently limiting to Antarctic plant distributions and productivity, and secondly, availability of this key resource is predicted to change with the onset of climate change. Nutrient availability is a second variable considered in this work, as there is evidence to suggest that nutrients also play a role in determining plant species distributions, and changes to nutrient balance and turnover rates are also expected in response to climate change. This work was conducted in the floristically important Windmill Islands region of East Antarctica, with the three Windmill Islands moss species Bryum pseudotriquetrum, Ceratodon purpureus and Grimmia antarctici forming its focus. A combination of field ecology, ecophysiology and laboratory studies were used to determine fine-scale patterns of present species distributions and their relationship to naturally occurring water and nutrient resource gradients, the impact of increased water and nutrients on a range of cryptogamic communities, and tolerance of desiccation biological profiles. A survey-based approach was used to determine species level patterns in bryophyte species distributions, and identify correlations with resource availability. Ten replicate transects, along community gradients, from pure bryophyte stands, through transitional moribund bryophyte zones, to lichen-dominated communities, were surveyed at two sites. The physical environment at each site was characterised by measurement of site soil properties, along with individual transect aspects and slopes. To determine the relationship between resource gradients and community patterns water and nutrient availability, along with a range of plant biochemistry measures indicative of the growth environment, were measured using a series of quadrats along each transect. Percent abundance for each species and/or vegetation category was determined for each quadrat by microscopic examination of field samples. The community gradient, covering the entire ecological range of past and present bryophyte occupation, was found to be accompanied by resource gradients that operated in opposing directions. Pure bryophyte communities existed under conditions of high water availability and low nutrient availability. Crustose lichen-dominated communities persisted under opposing environmental conditions, of low water availability and high nutrient availability. Grimmia antarctici dominated the wettest habitats but its distribution extended into the dry moribund zones, albeit in low levels of abundance. Bryum pseudotriquetrum occurred in consistent levels of abundance across the entire gradient, whilst C. purpureus was restricted to the driest habitats. Live bryophyte material was found to occur in moribund turf, supporting the potential for bryophyte regeneration under a future wetter climate. Regenerating turf showed potential to support high species diversity, as all four bryophytes survive in this zone. To investigate the likely impacts of a wetter climate on Antarctic terrestrial communities, four cryptogamic communities, pure bryophyte, moribund bryophyte, crustose and fructicose lichen-dominated communities were subject to a multi-season manipulative field experiment. Within each community type, eight replicate quadrats received increased water and/or nutrient availability over two consecutive summer seasons. A range of physiological and biochemical measurements were conducted in order to quantify the community response to the treatments and determine the extent of any nutrient and water limitation. Few multi-season manipulative field experiments have been conducted in continental Antarctica. Whilst an overall increase in productivity in response to water and nutrient additions was supported, productivity appeared to respond more strongly to nutrient additions than to water additions. Pure bryophyte and fructicose lichen communities also showed stronger positive responses to additions, identifying some communities that may be better able to adapt and prosper under the ameliorating conditions associated with a warmer, wetter future climate. Using a range of morphological, biochemical and physiological techniques, biological profiles related to desiccation tolerance were developed for the three bryophyte study species, providing measures of relative abilities to avoid, tolerate, recover from and survive desiccation. Ceratodon purpureus showed good desiccation avoidance characteristics, its photosynthetic efficiency remained high at low water contents and it was lipid rich, suggesting that this species is well adapted to survive a drying climate. Bryum pseudotriquetrum is also likely to survive drier conditions, as this species showed good desiccation avoidance, had a plastic response to desiccation, and contained stachyose, which is likely to assist in its survival of desiccation events. Conversely, G. antarctici showed poor desiccation avoidance, as photosynthetic efficiency required highest water contents and it contained few protective substances, this species is therefore least likely to survive a drying environment. This study provides a baseline from which future changes to the Windmill Islands cryptogamic communities can be monitored. A baseline incorporating fine-scale bryophyte species patterns is particularly useful, as this component of the cryptogamic community is likely to be highly sensitive to even small shifts in water availability and detection of change is likely to be more sensitive at fine- rather than broad-scales. Both water and nutrient resource availability was found to underlie regional bryophyte species distributional patterns. The dynamics of the Windmill Islands flora is therefore likely to shift in response to climate change as the availability of these key resources is altered. Under a wetter future climate, productivity is overall likely to increase but only certain cryptogamic communities are likely to thrive. Regeneration of moribund bryophytes appears likely only if the future moisture regime creates consistently moist conditions. Bryum pseudotriquetrum is most likely to survive both a drying climate and also a fluctuating climate, which is a highly likely scenario for the region. Under a drier climate, the Antarctic endemic, G. antarctici, is likely to be most adversely affected, as it dominates only the wettest communities and generally shows poor tolerance of desiccation. Conservation issues are therefore raised for this species, if the current drying trend continues, creating overall biodiversity concerns.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Manton, Erin Rebecca. "DNA barcoding the vascular plant flora of southern British Columbia". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/60195.

Testo completo

Abstract (sommario):

DNA barcoding is a tool for rapidly identifying species based on short, standardized sequences of DNA, for example in situations where this may be difficult using morphology alone. I assembled a core DNA barcode reference library for southern British Columbia, home to ~54% of the vascular plant species in Canada, using the core plastid barcode loci rbcL and matK, and assessed its utility for identifying species in this region. The library comprises 4,812 sequences obtained from field-collected and herbarium tissue samples, supplemented with sequences downloaded from BOLD and GenBank, with at least one sequence for 75.4% of the vascular plant species occurring below 50°N in British Columbia. Sequence recoverability was significantly higher for rbcL than for matK (93.5% and 80.2%, respectively), and only marginally lower for both markers when using herbarium specimens (90.5% for rbcL and 77.8% for matK), which demonstrates the future feasibility of using museum specimens for completing a southern BC barcode reference library. As a proxy for assessing marker effectiveness, I scored resolution at the level of species and genus using tests of monophyly for Neighbour Joining trees, and performed sequence similarity searches with BLASTn analyses, both for each locus separately and for a dual-locus marker system (rbcL+matK; scored as a cumulative percentage in the BLAST analyses). Ignoring species represented by singleton sequences, the highest overall level of discrimination (66.9% of species and 91.6% of genera) was achieved for BLASTn analysis of rbcL+matK together. This work represents a significant contribution to a nation-wide barcode database, and provides a preliminary platform for ecological and other applications requiring species identification, where traditional methods are not feasible.
Science, Faculty of
Botany, Department of
Graduate

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Sokmen, Atalay. "Novel bioactive leads from the Turkish flora via plant cell cultures". Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265592.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Hang, Ye. "Developing multi-layered, flowering Mediterranean plant communities using South African flora". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12433/.

Testo completo

Abstract (sommario):

The aim of this study was to create sown multi-layered communities of Mediterranean South African plants based on Fynbos and Renosterveld species. These communities were designed to test naturalistic design principles as to achieve long flowering designed plantings involving three canopy heights (tall, medium and low). Competition between shrubs/forbs/succulents and geophytes by using microcosm experiments mirrors the form of actual designed vegetation in practice. The experiments prior to the competition experiment provided the understanding of germination, winter cold and summer wetness tolerance of a large number of SA species (over 300 species) from Western Cape. All winter growing and summer dormant geophyte species had the capacity to emerge from autumn sowings, and some were able to do the same from spring sowing. Smoke treatment prior to sowing is effective on many forb and small shrub species from Fynbos and Renosterveld, but much less useful (or necessary) on geophyte species. Species such as Gladiolus carneus, Gladiolus tristis and Ixia curvata tolerated -8°C in winter 2010/11, and many more species survived -5°C in winter 2011/12. Bulbinella elata, Bulbinella elegans, Bulbinella nutans, Moraea tripetala, Kniphofia uvaria, Romulea atrandra and Romulea sabulosa suffered no loss at -5°C and no loss over summer 2012 (historically the wettest summer in the UK since 1910). Altitude and the resulting number frost days which individuals experience at the collection locations were critical factors influencing their winter mortality in Northern England. Habitat soil conditions and other environment factors are important in relation to their summer mortality. Species naturally occuring in Renosterveld and seasonally wet habitats are typically more wet tolerant response in Uk summers (i.e. many Bulbinella, Kniphofia, Gazania and Romulea species). Specific geographical provenances were explored to find more useful genotypes that can survive well in the UK. Species collected from the inland Roggeveld region, including the provenances Sutherland, Rooiwal, Groot Swartberg mountains, and the Komsberg, were the most successful species in response to winter cold in Sheffield. Fifteen plant community types were designed to access competition amongst 30 selected species in terms of mortality and biomass production within the studies main microcosm experiment. The most successful communities were generally those composed of tall canopy layer geophytes and forbs/shrubs. Geophytes suffered less mortality than shrub/forb/succulent species but contributed less biomass in the first two years, particularly in low height geophytes. Medium height geophytes formed a more extensive canopy and had higher competition capacity to increase their coverage and biomass in communities from the third year on. Species that did this included Watsonia ‘Tresco Dwarf Pink’, Gladiolus cardinalis and Watsonia schlechteri. Some small Fynbos and Renosterveld geophytes tested in the combinations demonstrated a degree of shade tolerance, as in Romulea komsbergensis, Ixia and Hesperantha species. These communities were managed by annual cutting in late summer-early autumn.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Harris, C. J. "Plant community change in the Montgomeryshire Canal in relation to succession theory". Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384373.

Testo completo

Abstract (sommario):

The water physico-chemistry, hydrology and plant communities in the Montgomeryshire Canal were examined for evidence of successional phenomena over a five year period and comparisons were made with previous studies. Plant communities changed in a manner which suggested that classical successional ideas were applicable to canals. The changes were readily distinguishable when a period of twenty years had passed but as the examined period was decreased the complexity of the sequence became more apparent. In a single year there were changes in the plant communities. A later stage of succession was indicated as the number of changes increased and the available energy and habitat niches were filled. Succession did not take place in a slow orderly manner but progressed as a series of jumps when the plants were released from inhibitory factors. These sudden changes were promoted by changes in the habitat due to climatic variation, removal of grazers or alterations in the water level. Where the most important inhibitory factors were unchanging, the succession proceeded to a climax community decided by those factors. The physico-chemical factors affecting the canal changed during the study period. The canal became more acidic due to the effects of a cold wet spring. The underwater light climate in un-navigated lengths was determined more by the amount of shade upon the water surface than by any other factor. Levels of suspended solids were relatively unimportant. Established plant communities showed a great resistance to change, despite being subjected to traumatic perturbations. Skim dredging of a site with a well established community structure did not change the course of the succession, but removed inhibiting factors such as anoxic material or grazing and promoted a more rapid change to reedswamp. In the .long term falling water levels had the same effect as raising of the bottom due to infill, but in the two routes towards a less aquatic system were different. Infill led to a moving band of depth sensitive plants whilst loss of water encouraged rapid creation of a reedswamp. The study confirmed that limited navigation is not detrimental to the species composition or the productivity. Eutrophication was a limiting factor creating an unique climax community.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Kloot, P. M. "Studies in the alien flora of the cereal rotation areas of South Australia /". Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phk655.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Solé-Senan, Xavier Oriol. "Plant diversity and ecosystem services in agricultural landscapes along different spatial scales". Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/406287.

Testo completo

Abstract (sommario):

Aquesta tesi té com a objectiu escatir fins quin punt les diversitats d'espècies i funcional de les comunitats de flora arvense canvien a escala de camp i de paisatge. A escala de camp, l'estudi s'ha focalitzat en l'anàlisi de l'efecte de la intensificació agrícola, depenent de la posició dins del camp i en funció del nivell de pertorbació en cada hàbitat que forma part del tradicional paisatge en mosaic en els ambients mediterranis. A escala de paisatge, hem analitzat els canvis en la diversitat al llarg de gradients d'heterogeneïtat en el paisatge, tenint en compte d'una banda l'heterogeneïtat composicional i per l'altra l'heterogeneïtat configuracional. L'aproximació basada en atributs biològics ens ha permès dirigir l'estudi a analitzar de quina manera afecten els canvis a la composició florística d'aquestes comunitats a la provisió dels serveis ecosistèmics que els agroecosistemes aporten a altres organismes.
La presente tesis tiene como objetivo dilucidar hasta qué punto la riqueza en especies y la diversidad funcional de las comunidades de flora arvense cambian a escala de campo y de paisaje. A escala de campo, el estudio se ha enfocado en el análisis del efecto de la intensificación agrícola, en cuanto a la posición en el campo y al nivel de perturbación en cada hábitat en la diversidad y funcionalidad de las comunidades de flora arvense. A escala de paisaje, hemos analizado los cambios en la diversidad a lo largo de gradientes de heterogeneidad en el paisaje, teniendo en cuenta por un lado la heterogeneidad composicional y por el otro la heterogeneidad configuracional. La aproximación basada en atributos biológicos nos ha permitido enfocar el estudio en cómo afectan los cambios en la composición florística de dichas comunidades a la provisión de los servicios ecosistémicos que los agroecosistemas aportan a otros organismos.
This thesis is aimed at disentangling the extent at which species richness and functional diversity of plant species from arable communities change at field and landscape scale. At field scale, the study was focused on the effects of agricultural intensification regarding field position and the level of disturbance at which such habitat is subjected on the diversity and functionality of arable plants community. At landscape scale, we assessed the diversity changes along gradients of landscape heterogeneity, taking into account on the one hand the surrounding compositional landscape heterogeneity and on the other hand the configurational landscape heterogeneity. The trait-based approach conducted allows us to focus on how shifts in species composition in such arable plant communities are expected to affect the delivery of the ecosystem services that these agroecosystems provide to other organisms.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Rowe, N. P. "The fossil flora of the Drybrook Sandstone (Lower Carboniferous) from the Forest of Dean, Gloucestershire". Thesis, University of Bristol, 1986. http://hdl.handle.net/1983/5ff3b8d0-8848-4f44-a5ea-bec0bf4a9daa.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Vanderplank, Sula E. "The Vascular Flora of Greater San Quintín, Baja California, Mexico". Scholarship @ Claremont, 2010. http://scholarship.claremont.edu/cgu_etd/2.

Testo completo

Abstract (sommario):

The plants of San Quintín (Baja California, Mexico) were documented through intensive fieldwork and the collection of herbarium specimens to create a checklist of species. This region is home to a diverse flora with high levels of local endemism and many rare plants. The flora documented in this study was compared to historical records from the region and shows the impact of agriculture and urbanization on the plants, including several extirpated species. A study of the perennial vegetation using a 1 km grid provides species distribution data for 140 native species, which were assessed to highlight areas of significant species richness for native, rare, and endemic taxa. Several non-native plants were also mapped to provide baseline data. Areas of conservation priority for the flora of Greater San Quintín are discussed in light of these combined findings.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Chilton, Earl Wallace. "Macroinvertebrate communities associated with selected macrophytes in Lake Onalaska : effects of plant type, predation, and selective feeding /". The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266691096246.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Hatchwell, Paul K. "A national biodiversity audit of conservation and management status of vascular plant flora in Mexico". Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402643.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Ramjukadh, Carla-Louise. "Are wetland plant communities in the Cape flora influenced by environmental and land-use changes?" Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/12974.

Testo completo

Abstract (sommario):

Includes bibliographical references.
Considerable attention has been given over the past few years to the distribution and environmental condition of wetlands in South Africa. A 1987-1989 study investigated over one hundred wetlands to establish unique discernible features for grouping and classifying wetlands in the Cape Floristic Region. In the current study, a representative subset of the wetlands surveyed in 1988/89 was re-examined. This thesis characterizes and assesses wetland plant communities and wetland types in both data sets, attempts to identify the major environmental factors influencing plant species distribution in the wetlands, assesses changes in plant species community composition over time; and asks whether surrounding land-use has influenced these. In the current study, of the 142 plants species recorded, 114 were identified to species with 28 to genus level. The historical vegetation data includes 173 plants, of which 115 were identified to species with 58 to genus level.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Levy, Foster, e James T. Donaldson. "Additions to the Vascular Flora of the Rocky Fork Tract, Tennessee, USA". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/5451.

Testo completo

Abstract (sommario):

An examination of previously unaccessioned and overlooked specimens has added 16 species to the vascular flora of the 3800 ha Rocky Fork Tract in northeastern Tennessee. One species was deleted because of a prior misidentification for a net gain of 15 species and a total of 764 species. One species, Solidago lancifolia (Torr. ex A. Gray) Chapm., is listed as Endangered in Tennessee. All additions except two, represent county records. ©2018 Botanical Research Institute of Texas.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Kumarage, Lakmini Darshika. "The biogeographic affinities of the Sri Lankan flora". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29550.

Testo completo

Abstract (sommario):

The island of Sri Lanka’s exceptional biodiversity and enigmatic biogeography begs investigation, as the island is key in understanding the evolution of the Asian tropical flora. Since the Jurassic, Sri Lanka has been subjected to remarkable tectonic changes, thus its flora could have been influenced by that of a number of nearby landmasses, as well giving Sri Lanka the potential to have played a wider role in the assemblage of floras elsewhere. Firstly, as Sri Lanka originated as a fragment of the supercontinent Gondwana, part of its flora may contain Gondwanan relict lineages. There is also the potential for immigration from Laurasia after the Deccan Plate collided with it 45-50 Mya. Further, Sri Lanka may harbour floristic elements from nearby land masses such as Africa and Southeast Asia as a result of long distance dispersals, and in situ speciation has the potential to have played an important role in enhancing the endemic Sri Lankan flora. I tested the relative contributions of the above hypotheses for the possible origins of the Sri Lankan flora using three representative families, Begoniaceae, Sapotaceae and Zingiberaceae. These families represent both herbaceous and woody elements, and have high diversity across the tropics. Dated molecular phylogenies were constructed for each family. I used recent analytical developments in geographic range evolution modelling and ancestral area reconstruction, incorporating a parameter J to test for founder event speciation. A fine scale area coding was used in order to obtain a better picture of the biogeography of continental Asia. Amongst all the models compared, a dispersal-extinction cladogenesis model incorporating founder event speciation proved to be the best fit for the data for all three families. The dates of origin for Sri Lankan lineages considerably post-date the Gondwanan break up, instead suggesting a geologically more recent entry followed by diversification of endemics within the island. The majority of Sri Lankan lineages have an origin in the Sunda Shelf (53%). Persistence of warm temperate and perhumid climate conditions in southwestern Sri Lanka resembling those of Peninsular Malaysia and Sumatra could have facilitated suitable habitats for these massive dispersals from the Sunda Shelf region. Some trans-oceanic long distance dispersals from Africa (11%) are also evidenced, again these are too young to accept a hypothesis of dispersal during the Deccan Plate’s migration close to the African coast during the late Cretaceous, but occurred later during the Miocene. Further, some lineages of Laurasian origin (20%) are evidenced in the Zingiberaceae with ancestral areas of China and Indochina, which is congruent with a post collision invasion. Among the families tested, dispersals have occurred stochastically, one during the Eocene, six during the Oligocene, seven during the Miocene, two during the Pliocene and one during the Pleistocene. The highest number of dispersals occurred during the Miocene when a warm climate was prevailing during the Miocene thermal maximum. My results confirm that in situ speciation is an important contributor to the Sri Lankan flora. More rapid radiation of endemics has occurred during Pliocene-Pleistocene; two endemics in Begoniaceae, ten endemics in Sapotaceae and ten endemics in Zingiberaceae have evolved in situ during this period. Sri Lanka will have been subjected to expansion and contraction of climatic and vegetation zones within the island during glacial and interglacial periods, potentially resulting in allopatric speciation. As a conclusion, long distance dispersals have played a prominent role in the evolution of the Sri Lankan flora. The young ages challenge the vicariant paradigm for the origin and current disjunct distributions of the world’s tropical lineages and provide strong evidence for a youthful tropics at the species level. The thesis contains six chapters; first two are introductory chapters, then there are three analytical chapters, one for each family, and finally a summary chapter is provided. Each analytical chapter is written as a stand-alone scientific publication, thus there is some repetition of relevant content in each.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Levy, Foster, e Elaine S. Walker. "Vascular Flora of the Rocky Fork Tract, Tennessee, USA, and Its Use in Conservation and Management". Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/709.

Testo completo

Abstract (sommario):

A flora of the 3800 ha Rocky Fork Tract in northeast Tennessee produced 749 species of which 19 were on the Tennessee Rare Plant List and 34 were on the Cherokee National Forest Species Viability List with 87 county records from Greene County and 217 from Unicoi County. Rare species were particularly numerous in the Cyperaceae and Orchidaceae. The tract serves as a refuge for several regionally uncommon species by supporting either large populations or metapopulations of these species. Exotic species comprised 15% of the flora and were most common in the Fabaceae and Poaceae. The most unique habitat was a heath bald dominated by Rhododendron catawbiense with abundant Xerophyllum asphodeloides in the herbaceous layer. While species richness was relatively high compared to regional sites of comparable area, diversity was limited by the absence of high elevation spruce-fir communities and the paucity of wetlands.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Golding, Janice Sarah. "Herbarium-based Trait Studies on Plant Extinction Risk in the Flora Zambesiaca Region, South-Central Africa". Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517144.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Kelani, Madeha Mohammed. "Antibacterial activity of some South African plant extracts against streptococcus mutans". University of the Western Cape, 2015. http://hdl.handle.net/11394/4745.

Testo completo

Abstract (sommario):

Magister Scientiae (Medical Bioscience) - MSc(MBS)
Good oral health has a major influence on the general quality of life and well-being. Several chronic and systemic diseases have been attributed to poor oral health. With the increasing incidence of oral diseases, the global need for alterative prevention and treatment methods and safe, effective, and economical products has expanded. There are many studies showed that Streptococcus mutans has been implicated as major etiological agent of dental caries. South African has very rich natural flora especially Cape region. Several South African medicinal plants have been used since immemorial time for treatment of different human pathologies including dental problems. The antibacterial activities of plants extracts have been recognized and documented scientifically during the last few decades. In this project we aimed at the screening of 31 South African plants randomly collected from Cape region for their antibacterial activity against Streptococcus mutans initially at two concentrations (500 and 100 µg/ml).MIC’s and MBC’s were determined for the active plant extracts, as well as the qualitative studies of the effect of the active extracts on the biofilm formation. The best or the most active safe plant (Psoralea fruticans) was submitted to chromatographic separation to isolate the bioactive compounds which could be responsible for such activity. Identification of the pure active compounds was carried out using different spectroscopic techniques. Finally the biological evaluation of the isolated pure compounds was measured against S. mutans and also the cytotoxicity studies in-vitro against normal cells lines was carried out.

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Luz, Cíntia Luíza da Silva. "Anacardiaceae R. Br. na flora fanerogâmica do estado de São Paulo". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-27042012-123436/.

Testo completo

Abstract (sommario):

O estudo da família Anacardiaceae tem o objetivo de contribuir com o plano mais amplo do levantamento da \"Flora Fanerogâmica do Estado de São Paulo\", que vem sendo subsidiado pela FAPESP desde 1994 e conta com a colaboração de pesquisadores de muitas universidades e institutos de pesquisa do Estado. As Anacardiaceae compreendem cerca de 81 gêneros e 800 espécies, presentes em ambientes secos a úmidos, principalmente em terras baixas nas regiões tropicais e subtropicais em todo o mundo, estendendo-se até as regiões temperadas. No Brasil a família encontra-se representada por 14 gêneros e 57 espécies. O levantamento das espécies foi realizado baseando-se nas coleções de Anacardiaceae do Estado de São Paulo depositadas nos herbários BHCB, BOTU, ESA, HRCB, MBM, IAC, PMSP, R, RB, SP, SPF, SPFR, SPSF e UEC, expedições de campo e consultas bibliográficas. Os resultados seguem o padrão da série \"Flora Fanerogâmica do Estado de São Paulo\". São apresentadas chaves de identificação para gênero e espécies, descrições morfológicas, ilustrações e dados sobre distribuição geográfica, habitat, variabilidade intraespecífica, período de floração e frutificação, grau de conservação das espécies e riscos de extinção. No Estado de São Paulo, há 12 espécies nativas distribuídas nos gêneros Anacardium, Astronium, Lithrea, Myracrodruon, Schinus, Spondias e Tapirira. Lithrea molleoides, Schinus terebinthifolius e Tapirira guianensis são as espécies mais amplamente distribuídas da família no Estado, sendo encontradas em quase todas as formações vegetacionais, inclusive em áreas antropizadas. Spondias mombin é encontrada na floresta Estacional Semidecidual e matas ciliares próximas ao rio Paraná, nas regiões noroeste e oeste do Estado. Schinus engleri é encontrada, no Estado de São Paulo, nas florestas Ombrófila Mista Alto-Montana de Campos do Jordão e da Serra da Bocaina e Schinus weinmannifolius ocorre nos cerrados e campos de Itararé e Itapeva, entre outros municípios localizados próximos à região sul-sudoeste do Estado de São Paulo. O gênero Anacardium é representado no Estado pelas espécies A. humile, planta com hábito geoxílico comum nos cerrados e A. occidentale, uma árvore pequena das restingas. Astronium graveolens e Myracrodruon urundeuva, assim como a maioria das espécies de Anacardiaceae, ocorrem nas Florestas Estacionais Semideciduais e nos cerrados do Estado de São Paulo. Um padrão de distribuição incomum é observado em Lithrea brasiliensis que, com exceção do material-tipo, não possui exemplares ulteriores do Estado de São Paulo depositados nos herbários consultados. Em relação ao grau de conservação das espécies, Lithrea brasiliensis deve ser categorizada como presumivelmente extinta (EX) e Myracrodruon urundeuva como quase ameaçada (NT), as demais espécies enquadram-se como espécies não ameaçadas, na categoria de preocupação menor (LC)
The present study on Anacardiaceae aims to contribute with the broader survey project of the Phanerogamic flora of the São Paulo state which. This great efford has been supported by FAPESP since 1993 and counts on the collaboration of researchers from many universities and institutes of the state. The family comprises ca. 81 genera and 800 species distributed mostly in lowlands, from dry to moist habitats, throughout the tropics and subtropics worldwide and also extending into the temperate zone. Iin Brazil Anacardiaceae is represented by 14 genera and 57 species. The present survey was carried out based on field work, bibliographical references on Anacardiaceae and examination of the collections from the following herbaria: BHCB, BOTU, ESA, HRCB, MBM, IAC, PMSP, R, RB, SP, SPF, SPFR, SPSF, UEC. The results are presented following the Phanerogamic flora of Sao Paulo State. We provide identification keys to genera and species, morphological descriptions, illustrations and additional data on distribution, habitat, intraespecific variability, periods of flowering and fruiting, species conservation status. In the area this family is represented by 12 native species belonging Anacardium, Astronium, Lithrea, Myracrodruon, Schinus, Spondias e Tapirira. Lithrea molleoides, Schinus terebinthifolius and Tapirira guianensis are the most common and widespread Anacardiaceae species of São Paulo state and they are collected in almost all types of vegetation, including disturbed areas. Spondias mombin occurs in Sazonal Semidecidous and Riparian Forests next to the Paraná River in the northwest and the west regions of the state. S. engleri is reported for São Paulo state in the High-Montane Mixed Ombrophylous Forest of Campos do Jordão and Serra da Bocaina and S. weinmannifolius is found in the \"cerrado\" and \"campos\" of Itararé, Itapeva and other cities located next to the south and the south-west regions of the state. Anacardium is represented in the state by two species, A. humile, a \"cerrado\" common plant with geoxylic habit, and A. occidentale, a \"restinga\" small tree. Astronium graveolens and Myracrodruon urundeuva, as well as the majority of Anacardiaceae species are collected in Sazonal Semidecidous Forests and \"cerrados\" of São Paulo state. An uncommon distribution pattern is found in Lithrea brasiliensis, which is reported for São Paulo state only from type-material. In relation to the species conservation status, Lithrea brasiliensis should be categorized as Presumably Extinct (EX) and Myracrodruon urundeuva as Near Threatened (NT). The other species are classified as Least Concern (LC) category

Gli stili APA, Harvard, Vancouver, ISO e altri

20

O'Donnell, James. "An ecological study of Preston Peak's flora : establishing baseline data for climate change research on subalpine vegetation /". View full-text version online through Southern Oregon Digital Archives, 2003. http://soda.sou.edu/awdata/040304a1.pdf.

Testo completo

Abstract (sommario):

Thesis (M.S.)--Southern Oregon University, 2003.
"A thesis submitted to the Department of Biology and the Graduate School of Southern Oregon University in partial fulfillment of the requirements for the degree of Master of Science in Environmental Education." Includes bibliographical references (leaves 93-89). Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Anderson, Pippin. "A biogeographic analysis of the seaweed flora of the west coast of southern Africa, from Lüderitz to Cape Agulhas". Bachelor's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/26388.

Testo completo

Abstract (sommario):

A biogeographic analysis of the seaweed flora of the area from Lüderitz to Cape Agulhas was undertaken. Biogeographic patterns were reviewed across 15 geographic regions. A TWINSPAN analysis showed a clear division of the area into two separate species communities. These two communities are the Benguela province, and the western overlap region between the Benguela and Agulhas provinces. The western overlap region was found to be the most diverse. Diversity was shown to decrease with a decrease in latitude. Patterns in endemism among the brown seaweeds follow this trend. In contrast to this, red and green endemics increase with a decrease in latitude. Shore distribution patterns were reviewed, and demonstrated an increase in diversity with a progression down the shore. Among the red seaweeds, this increase, with greater depth was considerable. Species distribution patterns in both shore and shore pool zones were found to follow the same pattern, except for a drop in species in the subtidal fringe pools, which this study concluded was a meaningless concept. These results have been reviewed in relation to present conservation areas along this shore, and future recommendations were made for location of sites for the conservation of seaweed. These were the formation of reserves between Lüderitz and Port Nolloth, between Yzerfontein and Melkbosstrand, and from Scarborough to Cape Hangklip. In some of these areas existing reserves need to make policy adjustments while in others reserves need to be established for the conservation of both diversity and uniqueness of seaweed species.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Schaefer, Heidi Laura. "A survey of Greenwich, Prince Edward Island National Park flora and suggestions for managing rare plant species". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0018/MQ49438.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Forster, Paul I. "The pursuit of plants : studies on the systematics, ecology and chemistry of the vascular flora of Australia and related regions /". [St. Lucia, Qld], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18317.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

24

O'Brien, Eileen M. "Climate and woody plant species richness : analyses based upon southern Africa's native flora with extrapolations to subsaharan Africa". Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670313.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Mollendorf, Miranda Andrea. "The World in a Book: Robert John Thornton's Temple of Flora (1797-1812)". Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11184.

Testo completo

Abstract (sommario):

I argue in my dissertation that Robert John Thornton's (1768?-1837) Temple of Flora (folio 1799-1807, quarto 1812), also entitled "The Universal Empire of Love," represents personified botanical flowers of the British Empire in a colonial microcosm where anthropomorphic plants are allegorized as Europe's others. This book was a collectible item with plates issued in a series of subscriptions, which were always bound in different combinations so that no two copies were ever the same--a book that depicts a metamorphic view of nature through a series of alterations made to the individual plates, which reflects the diversity of exotic and familiar territories in the world and the mysteries within it. Thornton chose plants, flower symbolism, and landscape backgrounds "with scenery appropriated to their subject," to encapsulate the universe as a series of botanical scenes of exotic and familiar territories of Britain's past and present, and this botanical world includes four continents of the world symbolically represented as women through the relationship between image and text, the diversity of people and naturalia within these territories, and the passage of historical and chronological time. TheTemple of Flora is a textual space that involves strategies of possessing and knowing nature through the collection and conquest of plants that represent the colonial inhabitants of the British Empire ensconced in their territories and collected by wealthy Britons as a miniature colonial and exotic world bound between two covers.
History of Science

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Vilhalva, Divina Aparecida Anunciação. "Estudo morfofisiologico do desenvolvimento das especies Galianthe grandifolia E. L. Cabral (Rubiaceae) e Campulocliniun chlorolepis Baker (Asteraceae) submetidas a diferentes concentrações de cadmio". [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314849.

Testo completo

Abstract (sommario):

Orientador: Angelo Luiz Cortelazzo
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-11T20:45:08Z (GMT). No. of bitstreams: 1 Vilhalva_DivinaAparecidaAnunciacao_D.pdf: 8473615 bytes, checksum: 16013933ce12bdce13be2d0f84d9563f (MD5) Previous issue date: 2008
Resumo: O acúmulo de metais pesados no solo provoca grandes danos ambientais, em especial o do cádmio, devido ao seu alto nível de toxicidade e efeitos acumulativos nos organismos em geral. Poucas pesquisas envolvendo a resposta de diferentes vegetais a metais pesados foram realizadas com espécies nativas de cerrado. O objetivo deste trabalho foi avaliar, em casa de vegetação, o comportamento de duas espécies do cerrado: Campulocliniumchlorolepis (Asteraceae) e Galianthe grandifolia (Rubiaceae) em relação ao excesso de cádmio (Cd) no solo. Ambas foram irrigadas com soluções aquosas contendo 0, 0,3 e 3 mmol L-1 de cádmio. Os resultados demonstraram que as espécies são diferentemente tolerantes às concentrações de cádmio a que foram submetidas. Campuloclinium chlorolepis suportou por 14 dias as concentrações de 0,3 e 3 mmol L-1 de Cádmio e, para estas mesmas concentrações, as plantas de Galianthe grandifolia, toleraram até 28 dias. Os principais sintomas de toxicidade do Cd foram: clorose, mancha e murchamento das folhas e inibição do crescimento em Campuloclinium chlorolepis; epinastia e manchas nas folhas em Galianthe grandifolia. O Cd não inibiu o crescimento de Galianthe grandifolia, havendo estímulo no crescimento das plantas até mesmo na maior concentração (3 mmol L-1 de Cd). A análise do teor de Cd mostrou que Galianthe grandifolia é mais tolerante e hiperacumuladora desse metal, concentrando em média 120,37 mg Kg¿1 nos tecidos da parte aérea e 298,97 mg Kg-1 de Cd na parte subterrânea. Campuloclinium chlorolepis apresentou concentrações maiores na parte aérea (22,07 mg Kg-1 de Cd) que nas raízes (7,97 mg Kg-1), mas inferiores às concentrações observadas na outra espécie. Neste trabalho foram também investigadas particularidades relevantes de ambas as espécies. Em Campuloclinium chlorolepis destaca-se a ocorrência de frutanos do tipo inulina, em forma de glóbulos e localizados em todos os tecidos de suas raízes tuberosas, com exceção da epiderme. No sistema subterrâneo de Galianthe grandifolia constatou-se a ocorrência de coléteres protegendo as gemas caulinares originadas em seu xilopódio. Ressalta-se também que as duas espécies possuem associação com fungos micorrízicos arbusculares e fungos endofíticos ¿Dark Septate¿, os quais são co-ocorrentes nas raízes tuberosas e finas de Campuloclinium chlorolepis, enquanto colonizaram apenas as raízes adventícias de Galianthe grandifolia.
Abstract: The accumulation of toxic metals in the soil brings forth great environmental damages, especially cadmium, due to its high toxicity and cumulative effects on the organisms in general. There are a few studies regarding heavy metals and Cerrado native species. The aim of this work was to assess the behavior of two Cerrado species cultivated in the greenhouse: Campuloclinium chlorolepis (Asteraceae) and Galianthe grandifolia (Rubiaceae), as affected by cadmium (Cd) excess in the soil. Both species were watered with aqueous solutions of 0, 0.3, and 3 mmol L-1 of Cd. The results showed that the species have different tolerance levels to the Cadmium concentrations to which they were submitted. Campuloclinium chlorolepis resisted during fourteen days, subjected to the concentrations of 0.3 and 3 mmol L-1 of Cadmium and, at these same concentrations, Galianthe grandifolia remained alive up to 28 days. The main symptoms of Cd fitotoxicity were: clorosis, stained and withered leaves and growth inhibition in Campuloclinium chlorolepis; epinasty and stained leaves in Galianthe grandifolia. There was no growth inhibition in Galianthe grandifolia, but rather growth stimulation, even in the highest concentration (3 mmol L-1 of Cd). The Cd content analysis revealed that Galianthe grandifolia is more tolerant and a hyperaccumulator of this metal, with a mean accumulation of 120.37 mg Kg-1 in the tissues of shoots, and 298.97 mg Kg-1 of Cd in the underground system. Campuloclinium chlorolepis showed greater concentrations of Cd in the shoots (22.07 mg Kg-1) rather than in the roots (7.97 mg Kg-1). In this work, peculiarities of both species were also analyzed. Globular inulin-type fructans were detected in all tissues of the tuberous roots of Campuloclinium chlorolepis, except for the epidermis. In the underground system of Galianthe grandifolia, the shoot buds sprouting from the xylopodium are protected by colleters. In addition, the two species showed an association with both arbuscular mycorrhizal fungi and dark septate endophytic fungi, which co-occur in the tuberous and the thin roots of Campuloclinium chlorolepis, but colonize only the adventitious roots of Galianthe grandifolia.
Doutorado
Doutor em Biologia Vegetal

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Carneiro, Paulo Henrique Marostegan e. "Caracterização florística, estrutural e da dinâmica da regeneração de espécies nativas em um povoamento comercial de Eucalyptus grandis em Itatinga, SP". Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11142/tde-22082002-152108/.

Testo completo

Abstract (sommario):

Os objetivos deste trabalho foram analisar a composição florística, a estrutura, alguns aspectos da dinâmica da regeneração de espécies nativas no sub-bosque de povoamentos comerciais de Eucalyptus spp e estudar o impacto que algumas práticas silviculturais (desbaste e corte raso) sobre a regeneração. Para isso, foram locadas 17 parcelas (0,68 ha de área amostral) em um talhão de Eucalyptus grandis (Talhão 48), na Fazenda São José do Bromado, coordenadas geográficas 23°1330S e 48°3407W, município de Itatinga SP. Na avalia ção da composição e estrutura da regeneração, realizada 30 meses após o corte da primeira rotação do povoamento de eucalipto, foram plaqueados e identificados todos os indivíduos arbóreos ou arbustivos com altura superior a 1,5m. O estudo da evolução temporal da regeneração foi realizado em 2 avaliações, 30 e 45 meses após a exploração do povoamento de eucalipto, utilizando o mesmo método de análise, sendo considerado morto o indivíduo amostrado nos levantamento anterior e não localizado na avaliação seguinte. Após a segunda avaliação as parcelas foram divididas em três tratamentos, sendo: Tratamento 1 testemunha (área amostral de 0,2ha), no qual o povoamento de eucalipto foi mantido, Tratamento 2 (área amostral de 0,24ha) no qual foi realizado o desbaste de 50% do povoamento de eucalipto e Tratamento 3 (área amostral de 0,24ha) no qual foi realizado o corte raso do eucalipto. Após a implantação dos tratamentos (46 meses após a exploração do povoamento) foram realizadas duas avaliações, a primeira 54 meses e a segunda 61 meses após a exploração da primeira rotação do povoamento de E. grandis. Foram amostrados 1900 indivíduos (104 espécies e 38 famílias) na primeira avaliação. A família de maior riqueza florística foi Myrtaceae seguida de Asteraceae, Fabaceae e Solanaceae, sendo esta última a que apresentou a maior densidade de indivíduos. As espécies de maior densidade relativa foram Solanum variabile e Matayba elaeagnoides. 76,66% dos indivíduos amostrados pertenciam a famílias que apresentaram padrão de distribuição espacial agregado. Na avaliação da dinâmica da regeneração, constatou-se que o recrutamento de novos indivíduos no sub-bosque do eucalipto no período de 30-45 meses da exploração comercial se concentrou nos grupos de espécies secundárias iniciais, secundárias tardias e espécies típicas da condição de sub-bosque. Enquanto a mortalidade se concentrou nos indivíduos pertencentes ao grupo das espécies pioneiras e das espécies não classificadas sucessionalmente. No período o índice para diversidade de Shannon (H´), apresentou crescimento de 3,48 para 3,573, e a equabilidade (J), crescimento de 0,751 para 0,762, mostrando que houve ganho em relação a diversidade de espécies na área. No estudo do impacto que diferentes práticas silviculturais impõem a regeneração, o tratamento 1 testemunha foi o que apresentou as menores taxas de mortalidade e o maior ingresso de espécies no período analisado. As operações de corte e remoção causaram grande impacto nos tratamentos 2 desbaste de 50% do povoamento de E. grandis e tratamento 3 corte raso, aumentando a taxa de mortalidade e diminuindo a taxa de recrutamento de indivíduos na regeneração. O Tratamento 2 foi o único a apresentar ganhos em diversidade (H) em todos os levantamentos.
The objectives of this study were to analyze a floristic composition, the structure, some aspects of the dynamics of regeneration of native species in understory of commercial stands of Eucalyptus spp and to study the impact that some silvicultural practices (thinning and clear cut) have on regeneration. For this purpose, 17 samples (0.68 ha total sample area) were located in a stand of Eucalyptus grandis (Stand 48), on the São José do Bromado Farm, geographical coordinates 23°1330S and 48°3407W, municipal of Itatinga, Sao Paulo. In the evaluation of the composition and structure of the regeneration, done 30 months after the clear cut of the first rotation of Eucalyptus grandis, all of the individual trees up to 1.5m of height were tagged and identified. The study of the temporal evolution of regeneration was done in 2 evaluations, 30 and 45 months after the clear cut of the stand. The same method of analysis was used, being that the individual trees measured previously and not found in the second evaluation were considered dead. After the second evaluation the samples were divided into three treatments: Treatment 1- control (sample area of 0.2ha), of which the trees were maintained, Treatment 2 (sample area of 0.24ha), of which 50% thinning was done, and Treatment 3 (sample area of 0.24ha), of which clear cut was done. After the implementation of the treatments (46 months after the exploration), two evaluations were accomplished. The first at 54 months and the second at 61 months, after the exploration of the first rotation of the stand. One thousand nine hundred trees (104 species and 38 families) were sampled in the first evaluation. The largest floristic family verified was Myrtaceae followed by Asteraceae, Fabaceae and Solanaceae, the family which presented the largest density of individuals. Whereas the species with the greatest relative density were Solanum variabile and Matayba elaeagnoides. Among the individual samples, 76.66% were of the families that present a pattern of aggregate spatial distribution. In evaluating the dynamics of regeneration, it was found that the recruitment of new individuals in understory of eucalyptus during the period of 30-45 months after the commercial exploration was focused on the groups of initial secondary species, late secondary and typical species of understory. The mortality was concentrated in the group of pioneer species and non-classified species, respectively. The index period to the Shannon diversity (H), presented growth of 3.48 to 3.573, and eqüability (J), growth of 0.751 to 0.762, showing to have gained in relation to the diversity of species of the area. The study of the impact that different silvicultural practices have on regeneration, treatment 1- presented the least incidence of mortality and the greatest incidence of species during the analysis period. The practices of thinning and clear cut caused a great impact on treatments 2 and 3, improving the incidence of mortality and decreasing the incidence of new individuals of regeneration. Treatment 2 was the only one to present gains in diversity (H) in all of the evaluations.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Artursson, Veronica. "Bacterial-fungal interactions highlighted using microbiomics : potential application for plant growth enhancement /". Uppsala : Dept. of Microbiology, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005127.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Dogan, Hakan Mete. "Understanding And Modeling Plant Biodiversity Of Nallihan (a3-ankara) Forest Ecosystem By Means Of Geographic Information Systems And Remote Sensing". Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1172436/index.pdf.

Testo completo

Abstract (sommario):

In this study, geographic information systems (GIS) and remote sensing (RS) tools were integrated and used to investigate the plant species diversity of the Nallihan forest ecosystem. Two distinct indices, Shannon Wiener and Simpson, were employed in order to express species diversity. The relationships between the indices and pertinent independent variables (topography, geology, soil, climate, supervised classes, and Normalized Difference Vegetation Index (NDVI) classes) were investigated to develop two distinct models for each index. After detecting important components with factor analysis, two models were developed by using multiple regression statistics. Running the models, two plant species diversity maps in grid format were produced. The validity of the models were tested by (1) mapping residuals to predict the locations where the models work perfectly, and (2) logical interpretations in ecological point of view. Elevation and climatic factors formed the most important component that are effective on plant species diversity. Geological formations, soil, land cover and land-use characteristics were also found influential for both models. Considering the disturbance and potential evapotranspiration (PET), the model developed for Shannon Wiener index was found out more suitable comparing the model for Simpson index.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Carregosa, Tamires 1989. "Diversidade de Leguminosae Juss. na restinga e nos tabuleiros de Pirambu, Sergipe, Brasil". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314801.

Testo completo

Abstract (sommario):

Orientador: Ana Maria Goulart de Azevedo Tozzi
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-26T03:22:52Z (GMT). No. of bitstreams: 1 Carregosa_Tamires_M.pdf: 7019188 bytes, checksum: 7c4b20b6a3aea43a65be0bd5859d3092 (MD5) Previous issue date: 2014
Resumo: A costa atlântica nordestina é formada por diversas formações vegetacionais, entre elas estão as restingas, que se desenvolvem sobre planícies arenosas costeiras, e os tabuleiros arenosos (Formação Barreiras), encontrados sobre baixos platôs nas adjacências das planícies costeiras. Em Sergipe, a faixa costeira possui 163 km de extensão, onde ocorrem, continuamente, as restingas e mais interiormente os tabuleiros, decorrentes de depósitos Terciários e constituídos predominantemente por sedimentos areno-argilosos. Alguns autores acreditam que a flora das restingas e da Formação Barreiras é formada por elementos presentes em seus ecossistemas adjacentes, mas principalmente da Floresta Atlântica, contribuindo para sua inclusão no Domínio Atlântico. Nem sempre os tabuleiros podem ser distinguidos das restingas, por apresentarem uma ampla variação fitofisionômica, ocorrerem em solos arenosos e compartilharem um número expressivo de espécies. A família Leguminosae figura em importância na constituição deste número de espécies. O presente estudo teve por objetivo o levantamento e tratamento taxonômico das espécies de Leguminosae das formações de restinga e tabuleiros de Pirambu, Sergipe. Adicionalmente, são incluidos dados sobre as relações de similaridade florística entre essas formações, novas ocorrências em Sergipe, períodos de floração, frutificação e síndrome de dispersão das espécies inventariadas. Foram realizadas expedições para coleta de material botânico entre julho de 2012 a setembro de 2013 e consultas às coleções do herbário ASE e UEC. Foram amostrados 55 táxons, distribuídos em 30 gêneros e 13 tribos. A subfamília Papilionoideae apresentou maior riqueza de gêneros e espécies (19 e 25, respectivamente). O gênero com maior número de espécies foi Chamaecrista (9 spp.), seguido por Senna, Inga, Mimosa e Stylosanthes (4 spp. cada). As áreas de tabuleiro apresentaram maior número de espécies de Leguminosae (43 spp.), seguidas das dunas (22 spp.) e antedunas (6 spp.), que representaram as restingas. Apenas quatro espécies ocorreram desde a região de antedunas até os tabuleiros. Dezesseis espécies registradas nos tabuleiros de Pirambu têm distribuição restrita ao território brasileiro, destas seis apresentam ocorrência restrita ao domínio Mata Atlântica
Abstract: The Brazilian northeastern Atlantic coast is formed by plural vegetative formations. Two of them are the "restinga", that develops in coastal sandy soils, and the "tabuleiro" (Barreiras Formation), found in low plateaus adjacent to coastal plains. In Sergipe, along all the shoreline, which is 163km in length, occur the "restinga" areas and, more interiorly, the "tabuleiro" areas, arising from Tertiary deposits and constituted predominantly of sandy clay sediments. Some authors believe that the flora of "restinga" and "tabuleiro" to be composed by elements from its adjacent ecosystems, mainly the Atlantic Forest, contributing to their inclusion in the Atlantic Domain. It is not always that the "tabuleiro" can be distinguished from "restinga", due to their shared species composition, wide physiognomic variation, and occurrence on sandy soils. The family Leguminosae figures in importance of species diversity in both habitats. This study aimed the inventory and taxonomic treatment of the species of Leguminosae in formations of "restinga" and "tabuleiro" areas in Pirambu, Sergipe. Additionally, floristic similarity between these formations, new records for the state, as well as flowering and fruiting phenology and dispersal syndrome for all legume species are presented. Expeditions for plant collection were conducted between July 2012 and September 2013 and consultation in herbaria ASE and UEC. Leguminosae is represented by 55 taxa (species and infraspecific taxa), 30 genera and 13 tribes in the coastal sandy formations of Pirambu. The Papilionoideae subfamily showed highest genus and species richness (19 and 25 respectively). The genus with the highest number of species was Chamaecrista (9 spp.), followed by Senna, Inga, Mimosa and Stylosanthes (4 spp. each). The "tabuleiro" areas had highest number of species of Leguminosae (43 spp.), followed by dunes (22 spp.) and antedunes (6 spp.), representing the "restinga". Only four species occurred from antidunes until "tabuleiros". Sixteen species recorded in the "tabuleiros" of Pirambu have restricted distribution within the Brazilian territory, which six of them are only known for the Atlantic Forest Domain
Mestrado
Biologia Vegetal
Mestra em Biologia Vegetal

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Elam, Caitlin Elizabeth. "Flora, Plant Communities, and Soils of a Significant Natural Area in the Middle Atlantic Coastal Plain (Craven County, North Carolina)". NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-11092007-123710/unrestricted/etd.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

32

McDonald, Leah E. "Plant Species of the Virginia Coastal Plain Flora that Are Disjunct from the Mountains: their Distribution, Abundance and Substrate Selectivity". W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1539626249.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Lubbe, Catherina Susanna. "Comparison of the urban domestic garden flora along a socio-economic gradient in the Tlokwe City Municipality / Catherina Susanna Lubbe". Thesis, North-West University, 2011. http://hdl.handle.net/10394/6589.

Testo completo

Abstract (sommario):

Urbanisation has increased tremendously over the last 60 years so that more than 50 per cent of the world population now live in cities. This is especially true for in developed countries, but it is expected that developing countries will take the lead in future urban population growth. This increasing trend of urbanisation has severe consequences for the environment, as it fragments and changes natural areas and alter environmental conditions. This has compelled scientists from many different disciplines to focus on the inclusion of humans into ecology as a driving force of change to create a better understanding of urban ecosystems. The diversity of fauna and flora in the urban environment provides a myriad of ecosystem goods (such as food and fuel) and services (e.g. cleaning the air and reducing noise levels). Apart from these tangible benefits, urban green space also provides recreational, educational and social benefits to urban inhabitants. A surprisingly substantial proportion (21‒36 %) of the total urban green space that produces these ecosystem goods and services is located in private yards. This portrays the importance of the flora of this land-use type, but very little is known about garden flora and its potential for conservation. The determinants of diversity and species richness in gardens were found to be different than for semi-natural ecosystems, because of the high anthropogenic influence. One of these is the socio-economic status of the inhabitants. People with higher socio-economic status were found to harbour more diverse species assemblages in their gardens than those of lower socio-economic status. This phenomenon was termed the “luxury concept”. In the Tlokwe City Municipality (TCM), the legacy effects of apartheid created a steep socio-economic gradient as a result of the inequitable distribution of economic, natural and social resources. The aims of this study were to gain information on the flora that is present in the domestic gardens of the TCM and to determine if socio-economic status (SES), a management index (MI) and demographic factors influences the distribution of plant species between these gardens. A total of 835 plant species were recorded from 100 domestic gardens and the majority were of alien origin. This large number of species included some Red Data species, invasive alien species and also many utilitarian species. This portrays gardens as important ex situ conservation habitats, but simultaneously it could also threaten the integrity of our natural ecosystems through the distribution of alien invasive species. The gamma, alpha and beta diversity were determined across five SES classes to describe the patterns of domestic garden plant species diversity in the TCM. In accordance with other studies, correlations showed that the SES of the inhabitants affected the plant species distribution in the study area. This was especially true for the distribution of alien species that are cultivated for their ornamental value. More species were found in areas of high SES than those of lower SES. The other aspect that influenced the distribution of plant species in these gardens were the MI, although this was to a lesser extent than the effect of SES. The confirmation of differences along the SES gradient could be utilised by urban planners and policy makers to correct this imbalance through the provision of urban green spaces where it is needed most.
Thesis (M. Environmental Sciences and Management)--North-West University, Potchefstroom Campus, 2011.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Egea, Marcelo Monge 1983. "As tribos Barnadesieae e Mutisieae s.l. (Asteraceae) no Estado de São Paulo, Brasil". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315174.

Testo completo

Abstract (sommario):

Orientador: João Semir
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-23T02:06:05Z (GMT). No. of bitstreams: 1 Egea_MarceloMonge_M.pdf: 5904313 bytes, checksum: dd7946172461917141bc355a9662d0bd (MD5) Previous issue date: 2011
Resumo: O presente trabalho apresenta o levantamento taxonômico das tribos Barnadesieae e Mutisieae s.l. (Asteraceae) ocorrentes no estado de São Paulo. Foram encontradas 55 espécies distribuídas em 14 gêneros e seis tribos. A Tribo Barnadesieae é composta pelos gêneros Barnadesia (01 sp.) e Dasyphyllum (13 spp.). Já a tribo Mutsisieae s.l. é composta pelas atuais tribos Gochnatieae, Mutisieae s.s., Nassauvieae, Stifftieae e Wunderlichieae. A tribo Gochnatieae está representada pelos gêneros Gochnatia (10 spp.) e Richterago (02 spp.). Da tribo Mutisieae s.s. foram encontrados os gêneros Chaptalia (06 spp.), Lulia (01 sp.), Mutisia (03 spp.) e Trichocline (03 spp.). Na tribo Nassauvieae são encontrados os gêneros Holocheilus (03 spp.), Jungia (02 spp.), Perezia (01 sp.) e Trixis (07 spp.). As tribos Stifttieae e Wunderlichieae são compostas por Stifftia (02 spp.) e Wunderlichia (01 sp.), respectivamente. Além disto, foram acumuladas novas informações sobre a taxonomia, distribuição e conservação dos táxons. Foram encontrados seis novos registros de ocorrência para o estado, Chaptalia graminifolia (Dusén ex Malme) Cabrera, Dasyphyllum fodinarum (Gardner) Cabrera, Dasyphyllum latifolium (Gardner) Cabrera, Dasyphyllum aff. vepreculatum (D. Don) Cabrera, a Holocheilus illustris (Vell.) Cabrera e Trixis verbascifolia (Gardner) Blake, além de mais quatro novos resgistros de ocorrência para outros estados. Dez espécies foram classificadas como raras no estado, Dasyphyllum candolleanum (Gardner) Cabrera, Dasyphyllum fodinarum (Gardner) Cabrera, Dasyphyllum lanceolatum (Less.) Cabrera, Dasyphyllum synacanthum (Baker) Cabrera, Dasyphyllum velutinum (Baker) Cabrera, Gochnatia sordida (Less.) Cabrera Holocheilus illustris (Vell.) Cabrera, Richterago polymorpha (Less.) Roque, Richterago radiata (Vell.) Roque e Wunderlichia mirabilis Riedel ex Baker. Oito espécies são consideradas presumivelmente extintas, Dasyphyllum lanceolatum (Less.) Cabrera, Dasyphyllum aff. vepreculatum (D.Don) Cabrera, Gochnatia floribunda Cabrera, Gochnatia orbiculata (Malme) Cabrera, Gochnatia rotundifolia Less., Gochnatia velutina (Bong) Cabrera, Holocheilus brasiliensis (L.) Cabrera e Lulia nervosa (Less.) Zardini. Somente G. rotundifolia está presumivelmente extinta (EX) na natureza. Gochnatia sordida (Less.) Cabrera foi redescoberta no estado após 180 anos, pois esta só era conhecida pelo material tipo. A única espécie endêmica do estado é Chaptalia hermogenis M.D. Moraes. É proposta uma lectotipificação, uma correção de autoria de espécie e uma correção do nome de espécie. São apresentadas descrições morfológicas, chaves de identificações para tribos gêneros e espécies, comentários sobre a morfologia e taxonomia
Abstract: This work presents the taxonomic treatment of the tribes Barnadesieae and Mutisieae s.l. (Asteraceae) which occur in São Paulo State. Fifty-five species belonging 14 genera and six tribes are recognised. The tribe Barnadesieae is composed by Barnadesia (01 sp.) and Dasyphyllum (13 spp.). The tribe Mutsieae s.l. is composed by the current tribes Gochnatieae, Mutisieae s.s., Nassauvieae, Stifftieae and Wunderlichieae. The tribe Gochnatieae is represented by Gochnatia (10 spp.) and Richterago (02 spp.). The tribe Mutisieae s.s. is composed by Chaptalia (06 spp.), Lulia (01 sp.), Mutisia (03 spp.) and Trichocline (03 spp.). In the tribe Nassauvieae are found Holocheilus (03 spp.), Jungia (02 app.), Perezia (01 sp.) and Trixis (07 spp.). The tribes Stifftieae and Wunderlichieae are composed by Stifftia (02 spp.) and Wunderlichia (01 sp.), respectively. We have found six new records for São Paulo, Chaptalia graminifolia (Dusén ex Malme) Cabrera, Dasyphyllum fodinarum (Gardner) Cabrera, Dasyphyllum latifolium (Gardner) Cabrera, Dasyphyllum aff. vepreculatum (D. Don) Cabrera, a Holocheilus illustris (Vell.) Cabrera and Trixis verbascifolia (Gardner) Blake, and four new records for other states. Ten rare species, Dasyphyllum candolleanum (Gardner) Cabrera, Dasyphyllum fodinarum (Gardner) Cabrera, Dasyphyllum lanceolatum (Less.) Cabrera, Dasyphyllum synacanthum (Baker) Cabrera, Dasyphyllum velutinum (Baker) Cabrera, Gochnatia sordida (Less.) Cabrera Holocheilus illustris (Vell.) Cabrera, Richterago polymorpha (Less.) Roque, Richterago radiata (Vell.) Roque and Wunderlichia mirabilis Riedel ex Baker. And eight extinct species, Dasyphyllum lanceolatum (Less.) Cabrera, Dasyphyllum aff. vepreculatum (D.Don) Cabrera, Gochnatia floribunda Cabrera, Gochnatia orbiculata (Malme) Cabrera, Gochnatia rotundifolia Less., Gochnatia velutina (Bong) Cabrera, Holocheilus brasiliensis (L.) Cabrera and Lulia nervosa (Less.) Zardini. Chaptalia hermogenis M.D. Moraes is the only one endemic species. It is proposed a lectotipification, a correction of an author's name and a correction of a name of a species. Descriptions and keys to tribe, genera and species, and comments on morphology and taxonomy are presented
Mestrado
Biologia Vegetal
Mestre em Biologia Vegetal

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Nualart, Dexeus Neus. "Els herbaris, fonts per al coneixement de la flora. Aplicacions en conservació i taxonomia". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/456806.

Testo completo

Abstract (sommario):

Les col·leccions botàniques constitueixen un registre permanent i ben documentat de la distribució de les plantes en el temps i l’espai. El seu ús ha evolucionat amb el pas del temps, des dels primers herbaris, utilitzats com a meres biblioteques de plantes, fins la actualitat quan han aparegut nous usos per els que no estaven destinats. En aquesta tesi doctoral s’ha avaluat com aquestes col·leccions poden contribuir a millorar el coneixement de la biodiversitat, i s’aporten estudis emmarcats en dues disciplines botàniques: la conservació i la taxonomia. En l’àmbit de la conservació es presenta un primer treball de síntesi sobre les múltiples potencialitats d’aquestes col·leccions a partir d’exemples bibliogràfics. En els dos altres treballs s’ha valorat la representació de la flora amenaçada de Catalunya en els herbaris; el primer esta basat en les col·leccions de l’herbari BC de l’Institut Botànic de Barcelona i el segon en les dels cinc principals herbaris públics de Catalunya. En ambdós estudis s’ha constatat que el nivell de representació d’aquesta flora en les col·leccions avaluades es molt elevat i s’ha donat a conèixer material inèdit que podrà ser d’utilitat per a la recerca i gestió d’aquesta flora amenaçada. En l’àmbit de la taxonomia, es presenten dos estudis sobre els tàxons proposats per Carlos Pau (1857-1937) per a la flora del Marroc, en el quals s’han revisat i documentat les sinonímies i avaluat la tipificació. La designació dels plecs tipus, en els casos en què ha estat necessària, ha de permetre l’estabilització dels noms per a la seva correcta aplicació. En conclusió, en aquesta tesi doctoral s’ha buscat posar de relleu la importància dels herbaris com font d’informació indispensables per a la gestió i conservació de les espècies amenaçades, així com per a estudis taxonòmic-nomenclaturals.
The botanical collections constitute permanent and well-documented distribution records of taxa through space and time. Their uses have advanced since the first collections regarded as mere libraries of plants until today when many new uses have arisen, including some for which the herbaria were initially not intended. In this thesis we have evaluated how these collections are useful to improve the biodiversity knowledge. Studies of two botanical disciplines, taxonomy and conservation, are provided. In the field of conservation, a synthesis paper about the multiple potentialities of these collections with different bibliographic examples is presented. The objective of the two other papers is to evaluate if the threatened flora of Catalonia is well represented in the herbaria. The first one is based on collections preserved in the BC herbarium of the Botanical Institute of Barcelona. The second one is based on collections preserved in the main public herbaria of Catalonia. In both studies, the percentage of representativeness of this flora obtained from the studied collections is very high. In addition unpublished data from the herbaria has been provided, which could be useful for research and management of this endangered flora. In the field of taxonomy, two studies of Moroccan taxa proposed by Carlos Pau (1857-1937) are presented. In these studies, we have reviewed and reported their synonymy and evaluated their typification. Type designation allows stabilizing their interpretation for a good application of these names. In conclusion, in this thesis, the importance of herbaria as essential source of information for management and conservation of endangered species and taxonomic and nomenclatural studies is revealed.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Althof, Arnhild Johanna. "Human impact on flora and vegetation of Kakamega Forest, Kenya structure, distribution and disturbance of plant communities in an East African rainforest /". [S.l.] : [s.n.], 2005. http://kola.opus.hbz-nrw.de/volltexte/2005/22.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Safont, Crespo Elisabet. "Flora and vegetation of the Guayana highlands : past dynamics, global warming and conservation guidelines = Flora i vegetació de les Terres de Guayana : dinàmica del passat, escalfament global i directrius de conservació". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/386460.

Testo completo

Abstract (sommario):

This thesis is aimed at the study of the flora and vegetation of the Guayana Highlands (GH), a set of -50 table mountains (called tepuis) located in the Guayana Shield of northern South America. Special emphasis is put on the potential upward migration of vascular plants as a response to global warming and the suggestion of conservation strategies. The tepui summits contain exceptional diversity and endemism of vascular plants, with more than 2400 known species, of which 30% would be endemics. In this study, the results of the Altitudinal Range Displacement analysis suggest that 30-50% of the GH endemic species could disappear due to total habitat loss by 2100 according to the most optimistic (B1) and pessimistic (A2) warming scenarios, respectively. An Environmental Impact Value has been calculated for each threatened species for a subsequent classification of these species into priority categories (10 for B1 and 13 for A2), which should be used in a chronological sequence to guide conservation and research actions. Subsequently, flora and vegetation approaches have been applied for the verification of the migratory phenomenon in the GH. Since this verification is based on the comparison of inventories conducted at different times, the first necessary step is to establish a baseline. The Roraima-tepui summit (2810 m elevation) has been selected for that purpose, as it is the best well-known tepui from the botanical point of view. The floristic survey of this tepuian summit has yielded 227 species, including 44 novelties since the publication of the Flora of the Venezuelan Guayana, one species new for science (Epidendrum sp. nov.), and 13 exotics, among which Poa annua and Polypogon elongatus (Poaceae) show the highest invasive potential. Five main plant communities have been identified: three herbaceous, one shrubland, and one forest formation, with their corresponding diagnostic species. An environmental characterization of these communities has been also performed. Finally, palaeoecological records may provide valuable information of the species' responses to past environmental changes, which is not available from short-term ecological observations. In this thesis, a palynological analysis of a sedimentary sequence from Uei-tepui (2150 m elevation) has been conducted to record the vegetation changes occurred in the last 2000 years in this tepui and to investigate the potential drivers involved. At -810 cal yr BP (AD 1140), a peak of fire incidence, coeval with a decrease in regional precipitation, reduced the woody elements of meadows (mainly Biophytum) and the Bonnetia cloud forests. Forest recovery to its previous abundance occurred slowly and elapsed several centuries to be completed after fire disturbance. In the mid-18th century, forests and meadows were replaced by Cyrilla racemiflora shrublands, coinciding with intense fires, synchronous with the arrival of Europeans to the Gran Sabana (GS) uplands. These results suggest that fire has been the main factor in the shaping of Uei¬tepui vegetation during the last two millennia. The documented local fire events were most likely caused by human activities and reached the summit from the GS, probably favoured by climatic conditions. The last local fire leading to forest clearing and the establishment of present-day vegetation most likely took place in the AD 1920s. The preservation of the GH flora in front of global warming should be addressed, at least partially, through ex situ conservation techniques, due to the nature of the threat (habitat loss). However, the documentation in this study of other human impacts (trampling on vegetation, exotic species, changes in soil properties, etc.) and the emergence of fire as a potential disturbing agent of the GH biome highlight that in situ conservation through protected areas may also be very important. A management plan with the involvement of local indigenous communities should be implemented in the GH region (i.e., lowlands, uplands and highlands), in order to reduce the risks posed by global warming, human impacts, and the potential synergy among them.
Aquesta tesi té com a objectiu l'estudi de la flora i la vegetació de les Terres Altes de Guayana (TAG), un conjunt de -50 muntanyes tabulars (anomenades tepuis) situades al nord d'Amèrica del Sud, amb especial èmfasi en la potencial migració altitudinal de les plantes vasculars com a resposta a l'escalfament global. Els cims dels tepuis contenen una diversitat i endemisme de plantes vasculars excepcional. Aquest estudi suggereix que el 30-50% de les espècies endèmiques de les TAG podrien desaparèixer per pèrdua total d'hàbitat cap a l'any 2100 segons els escenaris d'escalfament B1 (més optimista) i A2 (més pessimista), respectivament. S'ha calculat un Valor d'Impacte Ambiental per a cada espècie amenaçada per a la posterior classificació d'aquestes espècies en categories de prioritat (10 pel B1 i 13 per l'A2), les quals haurien de ser utilitzades en una seqüència cronològica per orientar les accions de conservació i recerca. Posteriorment, s'ha establert una línia base de diversitat florística, endemisme i vegetació al cim del Roraima-tepui per a la verificació del fenomen migratori a les TAG. L'inventari florístic d'aquest cim tepuià conté 227 espècies, incloent 44 nous registres, una espècie nova per a la ciència i 13 espècies exòtiques. S'han identificat cinc tipus de comunitats vegetals principals, amb les seves corresponents espècies diagnòstiques. També s'ha dut a terme una caracterització ambiental d'aquestes comunitats. Finalment, l'estudi paleoecològic de la seqüència sedimentària del Uei-tepui ha permès documentar la resposta de les espècies als canvis ambientals dels últims 2000 anys. Els resultats suggereixen que el foc ha estat el principal factor que ha modelat la vegetació del Uei durant aquest període. Els esdeveniments de focs locals molt probablement van ser causats per activitats humanes i van assolir el cim des de la Gran Sabana afavorits per les condicions climàtiques. La preservació de la flora de les TAG enfront de l'escalfament global s'hauria d'adreçar, com a mínim parcialment, mitjançant tècniques de conservació ex situ, a causa de la naturalesa de l'amenaça (pèrdua d'hàbitat). No obstant, la documentació en aquest estudi d'altres impactes humans (trepig de la vegetació, espècies exòtiques, canvis en les propietats del sòl, etc.) i l'aparició del foc com a potencial agent pertorbador del bioma tepuià posen de manifest que la conservació in situ mitjançant àrees protegides pot ser també molt important.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

RIBEIRO, Elâine Maria dos Santos. "Efeito de pertubações antrópicas crônicas sobre a diversidade da flora lenhosa da caatinga". Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/17412.

Testo completo

Abstract (sommario):

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-15T14:44:30Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Elâine_Ribeiro_TESE_PPGBV.final_V2.pdf: 8805946 bytes, checksum: 49c5072b57c8b0d0264ac0e02e425dc3 (MD5)
Made available in DSpace on 2016-07-15T14:44:30Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Elâine_Ribeiro_TESE_PPGBV.final_V2.pdf: 8805946 bytes, checksum: 49c5072b57c8b0d0264ac0e02e425dc3 (MD5) Previous issue date: 2015-02-25
FACEPE
Este estudo teve como objetivo investigar quais os efeitos de perturbações antrópicas crônicas (e.g. coleta de madeira e de produtos florestais não madeireiros, pastoreio extensivo, caça e danos causados à vegetação pela introdução de espécies exóticas que ocorrem em áreas remanescentes de floresta) sobre a diversidade taxonômica e filogenética da flora lenhosa da Caatinga. Inicialmente, investigamos como se dá a questão da perturbação crônica da flora e seus efeitos sobre a biodiversidade através da revisão de 51 artigos que tratam do tema. Verificamos que estes estudos, em sua maioria, foram realizados em países em desenvolvimento, cujas populações humanas utilizam a floresta para subsistência e comércio. Os efeitos da perturbação foram acessados principalmente ao nível de populações e comunidades, sendo a coleta de produtos florestais não madeireiros a fonte de impacto mais analisada. Os efeitos sobre a biodiversidade foram em geral negativos, mas efeitos neutros e positivos também foram registrados. O segundo capítulo traz um estudo de caso que verifica a influência das perturbações humanas crônicas sobre a diversidade e composição taxonômica da flora lenhosa da Caatinga, realizado em várias propriedades privadas na cidade de Parnamirim-PE, Brasil. Neste estudo foram amostradas comunidades lenhosas de adultos, jovens e plântulas, e como preditores da perturbação crônica utilizaram-se a densidade de pessoas e animais domésticos (caprinos e bovinos), além de indicadores de acessibilidade às áreas, como a distância ao centro urbano mais próximo, à estrada mais próxima e à propriedade rural mais próxima às parcelas amostradas. Esses preditores tiveram em geral efeitos negativos sobre a diversidade taxonômica independente do estágio ontogenético, sendo a densidade de pessoas e de animais os preditores mais importantes desses efeitos. Verificouse ainda que a composição das espécies nas áreas perturbadas foi distinta, sendo pouco representada pela abundância de espécies de madeira densa nas áreas mais perturbadas. O terceiro e último capítulo verificou como as comunidades lenhosas de adultos, jovens e plântulas da Caatinga, amostradas no capítulo anterior, são afetadas pela perturbação crônica do ponto de vista de diversidade e estrutura filogenética. Neste capítulo, utilizaram-se os mesmos preditores da perturbação citados anteriormente, porém agora combinados em um índice de perturbação crônica. A diversidade de famílias esperadas para história evolutiva da região e a distância média entre os indivíduos dessas comunidades, medida em anos, foi reduzida em ambientes mais perturbados e para todos os estágios ontogenéticos. As comunidades de jovens e de plântulas apresentaram maior grau de parentesco em áreas mais perturbadas, sendo os táxons Euphorbiaceae e Cnidoscolus responsáveis por esse aumento de parentesco. Os resultados desta tese demonstram que as perturbações antrópicas crônicas na Caatinga não podem ser negligenciadas, pois conferem efeitos negativos importantes à diversidade taxonômica e filogenética da flora lenhosa. Dessa forma, estratégias de manejo que conciliem o uso dessas florestas e a manutenção da biodiversidade da Caatinga são urgentes.
The aim of this study was to investigate the effect of chronic anthropogenic disturbances (e.g. harvesting of timber and non-timber forest products, hunting, livestock, and damage to vegetation caused by exotic species that occur in natural remnant forests) on the taxonomic and phylogenetic diversity of wood flora from Brazilian Caatinga. Initially, 51 scientific papers were revised in order to investigate how chronic anthropogenic disturbances affect the flora of natural ecosystems. Most studies were conducted at developing countries, where human populations use forest resources for subsistence and commerce. Chronic disturbance effects were accessed mainly at population and community levels, and harvesting of nontimber forest products was the disturbance source more frequently analyzed in those papers. Effects of the chronic disturbances were in general negative, however positive and neutral effects were also documented. The second chapter brings a case study that evaluates the influence of chronic disturbances on the taxonomic diversity and composition of Caatinga wood flora from private propreties at the municipality of Parnamirim-PE, Brazil. Adult, sapling and seedling of wood plant communities were sampled, and the density of people and livestock (goats and catle) near the plot were used as predictors of chronic disturbance, as well as the distances to the nearest urban centre, road and rural property. In general, these disturbance predictors showed negative effects on taxonomic diversity irrespective to ontogenetic stage. Moreover, the density of people and livestock near the plot were the main predictors of these negative effects. Species composition differed between plots with low and high level of disturbance, especially in relation to hard wood species, which were rare in the plots highly disturbed. The third and last chapter analyzed how the adult, sapling and seedling communities, surveyed previously, were affected by chronic disturbances from the viewpoint of the phylogenetic diversity and structure. In this chapter the chronic disturbance predictors described above were combined into a chronic disturbance index. The diversity of families expected to the local evolutionary history and the mean phylogenetic distance between the individuals were reduced in plots with higher level of disturbance for all ontogenetic stages. Sapling and seeedling communities had higher degree of relatedness in most disturbed sites, being Euphorbiaceas and Cinidoscolus taxa responsible for this increasing in the relatedness degree. Overall, this thesis demonstrates that chronic anthropogenic disturbance at Caatinga could not continue to be neglected, as it imposes deleterious effects to the taxonomic and phylogenetic diversity of wood plant assemblages. Management strategies conciliating forest use and the maintenance of Caatinga biodiversity are urgent.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Magalhães, Alessandra. "Perfil etnobotânico e conservacionista das comunidades do entorno da reserva natural Serra das Almas, Ceará - Piauí, Brasil". reponame:Repositório Institucional da UFC, 2006. http://www.repositorio.ufc.br/handle/riufc/15724.

Testo completo

Abstract (sommario):

MAGALHÃES, Alessandra. Perfil etnobotânico e conservacionista das comunidades do entorno da reserva natural Serra das Almas, Ceará - Piauí, Brasil. 2006. 68 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Pró-Reitoria de Pesquisa e Pós-Graduação, Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente - PRODEMA, Fortaleza-CE, 2006.
Submitted by demia Maia (demiamlm@gmail.com) on 2016-03-23T12:50:56Z No. of bitstreams: 1 2006_dis_amagalhães.pdf: 1794297 bytes, checksum: 8ede621dcb215bae53dc46c6ae9d1b08 (MD5)
Approved for entry into archive by demia Maia(demiamlm@gmail.com) on 2016-03-23T13:00:44Z (GMT) No. of bitstreams: 1 2006_dis_amagalhães.pdf: 1794297 bytes, checksum: 8ede621dcb215bae53dc46c6ae9d1b08 (MD5)
Made available in DSpace on 2016-03-23T13:00:45Z (GMT). No. of bitstreams: 1 2006_dis_amagalhães.pdf: 1794297 bytes, checksum: 8ede621dcb215bae53dc46c6ae9d1b08 (MD5) Previous issue date: 2006
The present study has subject out a diagnostic of therapeutic-use plants and characterization profile of the communities about conservation of the native flora at the region of Reserva Natural Serra das Almas, CE and PI, in Brazil. In order to do that, different pieces of information were investigated, such as the social-economical-cultural profile of the communities; the spread of ethnobotanical knowledge among successive generations; the ethnobotanical information of medicinal plants, data related to the epidemiological profile of the communities, to the trade of plants in urban areas, and on the existence of concern – on the conservationist point of view – about the local flora. Diferents types of halfstructured of questionary were carried to the populations of elect groups: 1) midwife, rootmen, witchdoctor, 2) young public of 15 to 25 years old, 3) servant of half post at the region of Reserva, 4) the businessman of medicinal plants to the free market of Crateús. Parallel of this interview, take effecting floristical survey of the species cultivated in the back yard and in the outskirts vegetation. The calculation of the ‘value of use’ of the medicinal plants was also carried out - in order to measure the level of importance of each plant to the communities of the studied areas. About the local flora were also researched. 61 medicinal species were cited, that to belong to 36 families, of which just 27 have been identified in genus level, because didn’t have botanic material in a reproductive condition. The families with the largest number of mentioned species were: Lamiaceae (8), following Euphorbiaceae (5), Anacardiaceae and Leg-Caesalpinioideae (4), Leg-Faboideae e Verbenaceae (3), Apocynaceae, Bignoniaceae, Moraceae, Olacaceae with 2 species each.. Medicinal plants are mainly used for the treatment of the flu, which is also the most frequently detected illness at health centers. Verified yet, that the largest part of plant used were the leaf. Some species have stood out for their high value of use, such as Plectranthus amboinicus (Lour.) Spreg (2,50), Himatanthus sp. (2,50), Ocimum gratissimum L. (2,00), Caesalpinia ferrea Mart (2,00), Licania rigida Benth (2,00). The results have shown a tendency towards the loss of ethnobotanical knowledge within young people.
O presente trabalho consiste diagnóstico de plantas com usos terapêuticos e caracterização do perfil de comunidades sobre a conservação da flora nativa do entorno da Reserva Natural Serra das Almas, CE e PI, Brasil. Para isto, investigou-se diversos aspectos como:o perfil sócio-econômico-cultural das comunidades; o repasse do conhecimento etnobotânico entre as sucessivas gerações; as informações etnobotânicas relativas ao uso das plantas medicinais, dados relativos ao perfil epidemiológico das comunidades; o comércio de plantas em área urbana; e sobre a existência de uma preocupação do ponto de vista conservacionista com a flora local. Foram aplicados diferentes tipos de questionários semi-estruturados para os grupos populacionais selecionados: 1) parteiras, curandeiros e raizeiros, 2) público jovem de 15 a 25 anos, 3) funcionários dos postos de saúde do entorno da reserva, 4) comerciantes de plantas medicinais da feira livre da sede municipal de Crateús. Paralelamente a essas entrevistas, foi realizado o levantamento florístico das espécies cultivadas nos quintais e na vegetação periférica às residências. Efetuou-se ainda, o cálculo do “Valor de Uso” das plantas usadas como medicinais, a fim de medir o grau de importância de cada uma, para as populações das comunidades analisadas. Foram citadas 61 espécies medicinais, pertencentes a 36 famílias, das quais, por falta de material botânico em estado reprodutivo, 27 só foram identificadas em nível de gênero. As famílias e subfamílias com maior número de espécies mencionadas foram: Lamiaceae (8), seguida por Euphorbiaceae (5), Anacardiaceae e Leg-Caesalpinioideae (4), Leg-Faboideae e Verbenaceae (3), Apocynaceae, Bignoniaceae, Moraceae e Olacaceae com 2 espécies cada. As plantas medicinais citadas são utilizadas principalmente para o tratamento das gripes, a qual constitui também a enfermidade mais freqüente detectada nos postos de saúde. Verificou também que as folhas foram as partes da planta mais usadas pelos entrevistados. Algumas espécies se destacaram pelo elevado valor de uso como: Plectranthus amboinicus (Lour.) Spreg (2,50), Himatanthus sp. (2,50), Ocimum gratissimum L. (2,00), Caesalpinia ferrea Mart (2,00), Licania rigida Benth (2,00). Os resultados demonstraram uma tendência à perda do conhecimento etnobotânico entre os jovens.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

MagalhÃes, Alessandra. "Perfil etnobotÃnico e conservacionista das comunidades do entorno da reserva natural Serra das Almas, CearÃ - PiauÃ, Brasil". Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2151.

Testo completo

Abstract (sommario):

O presente trabalho consiste diagnÃstico de plantas com usos terapÃuticos e caracterizaÃÃo do perfil de comunidades sobre a conservaÃÃo da flora nativa do entorno da Reserva Natural Serra das Almas, CE e PI, Brasil. Para isto, investigou-se diversos aspectos como:o perfil sÃcio-econÃmico-cultural das comunidades; o repasse do conhecimento etnobotÃnico entre as sucessivas geraÃÃes; as informaÃÃes etnobotÃnicas relativas ao uso das plantas medicinais, dados relativos ao perfil epidemiolÃgico das comunidades; o comÃrcio de plantas em Ãrea urbana; e sobre a existÃncia de uma preocupaÃÃo do ponto de vista conservacionista com a flora local. Foram aplicados diferentes tipos de questionÃrios semi-estruturados para os grupos populacionais selecionados: 1) parteiras, curandeiros e raizeiros, 2) pÃblico jovem de 15 a 25 anos, 3) funcionÃrios dos postos de saÃde do entorno da reserva, 4) comerciantes de plantas medicinais da feira livre da sede municipal de CrateÃs. Paralelamente a essas entrevistas, foi realizado o levantamento florÃstico das espÃcies cultivadas nos quintais e na vegetaÃÃo perifÃrica Ãs residÃncias. Efetuou-se ainda, o cÃlculo do âValor de Usoâ das plantas usadas como medicinais, a fim de medir o grau de importÃncia de cada uma, para as populaÃÃes das comunidades analisadas. Foram citadas 61 espÃcies medicinais, pertencentes a 36 famÃlias, das quais, por falta de material botÃnico em estado reprodutivo, 27 sÃ foram identificadas em nÃvel de gÃnero. As famÃlias e subfamÃlias com maior nÃmero de espÃcies mencionadas foram: Lamiaceae (8), seguida por Euphorbiaceae (5), Anacardiaceae e Leg-Caesalpinioideae (4), Leg-Faboideae e Verbenaceae (3), Apocynaceae, Bignoniaceae, Moraceae e Olacaceae com 2 espÃcies cada. As plantas medicinais citadas sÃo utilizadas principalmente para o tratamento das gripes, a qual constitui tambÃm a enfermidade mais freqÃente detectada nos postos de saÃde. Verificou tambÃm que as folhas foram as partes da planta mais usadas pelos entrevistados. Algumas espÃcies se destacaram pelo elevado valor de uso como: Plectranthus amboinicus (Lour.) Spreg (2,50), Himatanthus sp. (2,50), Ocimum gratissimum L. (2,00), Caesalpinia ferrea Mart (2,00), Licania rigida Benth (2,00). Os resultados demonstraram uma tendÃncia Ã perda do conhecimento etnobotÃnico entre os jovens.
The present study has subject out a diagnostic of therapeutic-use plants and characterization profile of the communities about conservation of the native flora at the region of Reserva Natural Serra das Almas, CE and PI, in Brazil. In order to do that, different pieces of information were investigated, such as the social-economical-cultural profile of the communities; the spread of ethnobotanical knowledge among successive generations; the ethnobotanical information of medicinal plants, data related to the epidemiological profile of the communities, to the trade of plants in urban areas, and on the existence of concern â on the conservationist point of view â about the local flora. Diferents types of halfstructured of questionary were carried to the populations of elect groups: 1) midwife, rootmen, witchdoctor, 2) young public of 15 to 25 years old, 3) servant of half post at the region of Reserva, 4) the businessman of medicinal plants to the free market of CrateÃs. Parallel of this interview, take effecting floristical survey of the species cultivated in the back yard and in the outskirts vegetation. The calculation of the âvalue of useâ of the medicinal plants was also carried out - in order to measure the level of importance of each plant to the communities of the studied areas. About the local flora were also researched. 61 medicinal species were cited, that to belong to 36 families, of which just 27 have been identified in genus level, because didnât have botanic material in a reproductive condition. The families with the largest number of mentioned species were: Lamiaceae (8), following Euphorbiaceae (5), Anacardiaceae and Leg-Caesalpinioideae (4), Leg-Faboideae e Verbenaceae (3), Apocynaceae, Bignoniaceae, Moraceae, Olacaceae with 2 species each.. Medicinal plants are mainly used for the treatment of the flu, which is also the most frequently detected illness at health centers. Verified yet, that the largest part of plant used were the leaf. Some species have stood out for their high value of use, such as Plectranthus amboinicus (Lour.) Spreg (2,50), Himatanthus sp. (2,50), Ocimum gratissimum L. (2,00), Caesalpinia ferrea Mart (2,00), Licania rigida Benth (2,00). The results have shown a tendency towards the loss of ethnobotanical knowledge within young people.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Alshibani, Salah Ramadan. "Screening of Selected Libyan Medicinal Plants for the Synthesis of Metal Nanoparticles and their activity against Streptococcus mutans". University of the Western Cape, 2020. http://hdl.handle.net/11394/7716.

Testo completo

Abstract (sommario):

>Magister Scientiae - MSc
Nanotechnology has emerged as an elementary division of modern science and stemmed directly from green chemistry twelve basic concepts, it receives global attention due to its unique character and ample applications. It also has great potential to mitigate the challenges they face in various fields, especially medical sector. Nanodrugs are increasingly considered as a potential candidate to carry therapeutic agents safely into a targeted compartment in an organ, particular tissue or cell. In this study, twenty (20) Libyan plants were selected and evaluated for their potential to synthesis gold and silver nanoparticles. The screening of the different plant extracts was performed using 96 well plate method at 25 °C and 70 °C. The NPs formation was confirmed and characterized using UV- Vis, DLS, HR-TEM and EDX. A well-defined NPs were obtained at high temperature (70 °C). The Au NPs had an average diameter of 92 nm at 25 °C and 66 nm at 70 °C. The zeta potential values were observed to be negative (-14 to -24) and indicate the stability of the Au NPs. The HR-TEM showed polydispersity, which decreased at higher temperature (70 °C). The stability of Au NPs in nutrient broth prior was conducted as well. All the Au NPs under study showed stability, only minimal changes in the UV-Vis spectra can be observed. Two plant extract viz Pistacia atlantica, Junipers phoenicea showed consistent results and forming stable and smaller NPs compared to others, both of the plant extracts and the corresponding NPs were tested against Streptococcus mutans and showed MIC value ~ 49 g/mL. In case of silver NPs, two plant extracts viz J. phoenicea, Rosmarinus officinalis, showed superior results than the others; both plants produced stable and small Ag NPs. The antibacterial activity against S. mutans demonstrated MIC valus ~ 50 g/mL. The synthesised NPs showed a promising bioactivity for developments of new antibacterial agents against S. mutans strains. Dose-dependent activity was observed for the tested NPs.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Betsch, Brody Bly. "A Study of the Impacts of Dutch elm disease, Emerald ash borer, and Amur honeysuckle on the Flora of Rush Run Wildlife Area". Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1564514690185145.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

43

José, María Domínguez Laura. "La intensificació agrícola i la diversitat vegetal en sistemes cerealistes de secà". Doctoral thesis, Universitat de Barcelona, 2011. http://hdl.handle.net/10803/80746.

Testo completo

Abstract (sommario):

La intensificació agrícola a escala de camp i de paisatge ha comportat la disminució de la riquesa de les comunitats vegetals i canvis en la composició florística. Per tal de revertir aquesta pèrdua de diversitat dels sistemes agrícoles i poder desenvolupar programes de gestió eficients, és important entendre l’efecte de la intensificació a ambdues escales sobre la diversitat vegetal i la manera com interactuen. En aquesta tesi s’ha abordat el paper de la intensificació agrícola a diferents escales espacials (paisatge i camp) sobre la diversitat vegetal dels conreus de cereals de secà de Catalunya en diferents posicions del camp (centre, vora i marge) que difereixen en la intensitat de la pertorbació i en la proximitat als hàbitats adjacents. Amb aquesta finalitat, s’ha mostrejat 29 camps de cereals d’hivern amb gestió ecològica i 29 amb gestió convencional situats en un gradient de complexitat del paisatge. A més, s’ha estudiat experimentalment l’efecte de les pràctiques agrícoles (control de la flora arvense i la fertilització) sobre la diversitat vegetal de les vores dels conreus. L’anàlisi de la diversitat vegetal s’ha realitzat des del punt de vista de l’estructura i la composició de les comunitats vegetals. L’estructura s’ha estimat a partir de la riquesa d’espècies de la vegetació aèria establerta i del banc de llavors del sòl, la biomassa aèria i el nombre de llavors del sòl. La composició s’ha avaluat a partir de les similituds florístiques entre els inventaris i les característiques morfològiques (formes biològiques i de creixement) i funcionals (pol•linització i disseminació pel vent) de les plantes. Els nostres resultats evidencien que la distribució de la vegetació, pel que fa a la riquesa d’espècies, la seva abundància i composició, està fortament influenciada per la posició dins del camp. A més, la complexitat del paisatge també afecta les comunitats vegetals, tot i que la seva influència disminueix a mesura que ens endinsem en el cultiu. També hem constatat que la gestió afecta de forma notòria la diversitat vegetal dels agrosistemes estudiats, però la seva importància es complementària a la del paisatge. Aquests patrons els atribuïm al diferent impacte de las pràctiques agrícoles i del paisatge a cada una de les posicions. La gestió s’intensifica des del marge cap al centre dels cultius, dificultant la viabilitat de moltes espècies, mentre que la importància dels hàbitats adjacents com a font de diàspores disminueix a mesura en endinsar-nos cap a l’interior del camp. Pel que fa a l’efecte de las pràctiques agrícoles sobre las comunitats vegetals dels cultius, hem constatat que els herbicides exerceixen un paper fonamental en el control de la flora arvense i que l’origen de la sembradura es també un determinant principal de la riquesa i abundància d’aquestes comunitats. A més, quan els nivells d’infestació d’arvenses són baixos, ni la grada de pues flexibles ni la fertilització no tenen un efecte significatiu sobre la flora arvense. Finalment ressaltar el paper positiu, tot i que moderat, de les rotacions complexes sobre el banc de llavors, ja que redueixen la densitat de llavors del sòl, i per tant futurs problemes d’infestacions de males herbes, sense afectar la riquesa de espècies. Com a conclusions principals podem destacar la necessitat de minimitzar la intensificació agrícola, tant a escala de camp com de paisatge, per preservar la biodiversitat dels agrosistemes. Tot i així, cal tenir en compte la necessitat de gestionar més adequadament la flora arvense per evitar futures infestacions i els problemes que en deriven. En aquest sentit, cal millorar les tècniques de neteja de llavors quan es reutilitza la pròpia collita i potenciar la rotació de cultius.
Agricultural intensification, at field and landscape scales, has caused a decrease in weed richness and changes in species composition. This study assessed the effects of agricultural intensification at different scales (landscape and field) on plant diversity in Mediterranean dryland cereal fields, to propose management practices that help mitigating the loss of biodiversity in such agroecosystems. To this end, 29 organic and 29 conventional fields distributed along a gradient of landscape complexity were surveyed. We focused on plant assemblages at three contrasted field positions (centre, edge and boundary), analysing species richness, floristic similarities and the relative abundance of various functional attributes (different life forms, growth forms, wind-pollinated species and wind-dispersed species). Seedbank size and species richness at the edges and centres were also assessed. Moreover, we experimentally evaluated the effects of weed control practices and fertilisation on weed flora and on crops at crop edges. Our results show that plant distribution is strongly affected by field position. Moreover, plant communities also respond to landscape complexity and field management, although their importance in different positions changes: landscape effect decreases while entering in the field and management plays a complementary role. These patterns respond to the limited dispersal range of seeds from nearby areas and increasing management intensity from the boundary to the centre of the fields. With regards to the effects of specific management practices on weed flora, our results highlight that the main factor shaping weed communities are herbicides, and that seed origin also strongly affects weed richness and abundance, whereas under low weed levels fertilisation and weed harrowing have little effect on diversity. Moreover, complex rotations are a good tool for seedbank management, because they do not affect species richness while they reduce seed abundance. Our study indicates that if we want to preserve agricultural biodiversity it is equally important to prevent agricultural intensification at landscape and field scale. Besides, more accurate weed management is needed to avoid weed infestations, e.g. improving seed cleaning procedures and performing complex rotations.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Nghidinwa, Kirsti C. "Why are some species invasive? : determining the importance of species traits across three invasion stages and enemy release of southern African native plants in New Zealand". Lincoln University, 2009. http://hdl.handle.net/10182/1438.

Testo completo

Abstract (sommario):

There are many factors that have been proposed to contribute to plant invasiveness in nonnative ecosystems. Traits of invading species are one of them. It has been proposed that successful species at a certain invasion stage share particular traits, which could be used to predict the behaviour of potentially invasive plants at the respective stage. Three main stages of invasion are distinguished: introduction, naturalization, and invasion. I conducted a stageand trait-based analysis of available data for the invasion of New Zealand by the flora of southern Africa. Using 3076 southern African native vascular plant species introduced into New Zealand, generalised linear mixed model analysis was conducted to assess association of several species traits with the three invasion stages. The results showed that plant traits were significantly associated with introduction but fewer traits were associated with naturalization or invasion, suggesting that introduction can be predicted better using plant traits. It has been also hypothesized that species may become invasive in non-native ecosystems because they are removed from the regulatory effects of coevolved natural enemies (Enemy Release hypothesis). A detailed field study of the succulent plant Cotyledon orbiculata var. orbiculata L. (Crassulaceae) was conducted in the non-native New Zealand and native Namibian habitats to compare the extent of damage by herbivores and pathogens. C. orbiculata is a southern African species that is currently thriving in New Zealand in areas seemingly beyond the climatic conditions in its native range (occurring in higher rainfall areas in New Zealand than are represented in its native range). As hypothesised, C. orbiculata was less damaged by herbivores in New Zealand but, contrary to expectation, more infected by pathogens. Consequently, the plant was overall not any less damaged by natural enemies in the non-native habitat than in its native habitat, although the fitness impacts of the enemy damage in the native and invaded ranges were not assessed. The results suggest that climatic conditions may counteract enemy release, especially in situations where pathogens are more prevalent in areas of higher rainfall and humidity. To forecast plant invasions, it is concluded that species traits offer some potential, particularly at the early stage of invasion. Predicting which introduced plants will become weeds is more difficult. Enemy release may explain some invasions, but climatic factors may offset the predictability of release from natural enemies.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Pereira, Ismael Martins. "Ecologia, conservação e aspectos taxonômicos do gênero neotropical Davilla Vand. (Dilleniaceae)". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/59/59139/tde-30072014-110731/.

Testo completo

Abstract (sommario):

Neste trabalho realizou-se o estudo de distribuição, riqueza e conservação do gênero Davilla Vand. (Dilleniaceae) no Neotrópico. Para tal utilizou-se a modelagem de distribuição de espécies com o algoritmo Maxent. Este produz distribuição das espécies no espaço geográfico a partir de dados ambiental e de ocorrência. Foram estudadas as espécies de acordo com o bioma de ocorrência: Mata Atlântica; Cerrado; e Amazônia. Este grupo está representado no Neotrópico por 25 espécies. Para o Cerrado incluiu-se além das espécies do gênero Davilla as demais espécies da família Dilleniaceae. Os resultados indicaram que no Cerrado o grupo está representado por nove espécies de Davilla, além de Curatella americana L. e três espécies de Doliocarpus Rol., destas cinco são endêmicas (Doliocarpus elegans Eichler e 4 Davilla spp.). Para a Mata Atlântica ocorrem 12 espécies de Davilla, oito delas são endêmicas, incluindo uma espécie ameaçada de extinção. Para a Floresta Amazônica são conhecidas nove espécies, cinco delas endêmicas. Duas outras espécies são Neotropicais, portanto, compartilhadas por todos os biomas citados anteriormente. As demais espécies são de ocorrência em pelo menos dois biomas. Para estes três biomas produziu-se a distribuição e a riqueza de espécies visando comparar os resultados com as unidades de conservação, objetivando discutir questões relativas à conservação deste grupo. Os parâmetros conservacionistas como espécies raras, zonas de endemismo, zonas de alta riqueza, áreas de preservação ambiental, foram confrontados objetivando indicar áreas prioritárias para a conservação do grupo e da biodiversidade. Os resultados indicaram existir três centros de diversidade para este grupo. O principal deles está localizado na Mata Atlântica, principalmente nas florestas litorâneas do estado da Bahia. Outro centro de diversidade localiza-se na região central do Cerrado, especialmente nos estados de Goiás e Bahia. A outra área de diversidade localiza-se próximo à foz do Rio Amazonas e ao longo de seu curso. Devido ao hábito predominante das espécies serem lianas, estas são importantes componentes das florestas, das quais usamos este referencial para discutir questões relativas à conservação destes habitats, de suas espécies e da biodiversidade. As informações completas estão apresentadas nos capítulos de acordo com os respectivos biomas abordados.
In this study was realized to study the distribution, richness and conservation of the Davilla Vand. (Dilleniaceae) in the neotropics. For this purpose was used to distribution model of species with Maxent algorithm. This produces species distribution in geographic in space based on environmental and occurrence data. Species in accordance with biome of occurrence were studied: Atlantic Forest; Cerrado; and the Amazon. This group is represented by 25 species in the neotropics. For the Cerrado was included in addition to the Davilla species all species of Dilleniaceae family. The results indicated that in the Cerrado this group is represented by nine species of Davilla, and Curatella americana L. and three species of Doliocarpus Rol., to these five are endemic (Doliocarpus elegans Eichler and 4 Davilla spp.). For Atlantic Forest occur 12 Davilla species, eight of which are endemic, including an endangered species. For the Amazon are known nine species, five of these endemic. Two other neotropical species are therefore shared by all biomes mentioned above. The other species are occurring in at least two biomes. For these three biomes produced the distribution and species richness in order to compare the results with the protected areas, aiming to discuss issues relating to the conservation of this group. Conservationists parameters as rare species, areas of endemism, areas of high species richness, conservation areas, were confronted aiming indicate priority areas for conservation of biodiversity and too this group. The results indicated three centers of diversity for this group. The main one is located in the Atlantic Forest in coastal forests of Bahia. Another center of diversity is located in central region of Cerrado, especially in the states of Goias and Bahia. The other area of diversity is located near the mouth of the Amazon River and along its course. Due to the prevailing habit of the species are lianas, these are important components of forests, of which we use this framework to discuss issues relating to the conservation of these habitats, their species and biodiversity. Full details are presented in chapters according to their biomes addressed.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Domènech, Ferrés Marta. "Cartografia de les congestes i ecologia de les comunitats vegetals de les congesteres d'Andorra (Pirineus)". Doctoral thesis, Universitat de Lleida, 2012. http://hdl.handle.net/10803/117075.

Testo completo

Abstract (sommario):

El canvi climàtic està afectant a la reducció de la coberta de neu, al retrocés de glaciars i a la desaparició de congestes en zones de muntanya. En aquest sentit, la congestera és un dels hàbitats més amenaçats als Pirineus. En aquesta Tesi Doctoral s’ha realitzat la primera cartografia de congestes d’Andorra (Pirineus) estudiant-ne les variables físiques que afecten a la seva formació i conservació i se n'ha obtingut un mapa que permetrà avaluar la dinàmica futura de les mateixes. El període climàtic d’acumulació de la neu (gener-abril) ha resultat ser determinant en el nombre i extensió de les congestes, quan aquest és fred i humit. Per tant un augment de temperatura o una disminució de la precipitació, en els mesos d’acumulació de neu, suposarien una disminució important en l’extensió i el nombre de congestes. Aquesta cartografia, que ha permès inventariar fins a 2.520 congestes, ha assentat les bases per estudiar la vegetació de les congesteres (composició, diversitat, fenologia i trets funcionals) a fi de relacionar-la amb les variables ambientals i poder preveure les principals conseqüències del canvi climàtic. En l’estudi de la vegetació, s’han inventariat fins a 85 plantes vasculars, 31 de les quals són típiques de la vegetació de pastures d’alta muntanya, i 21 són típiques de les congesteres (classe Salicetea herbaceae). S’han identificat fins 16 briòfits, 2 dels quals han estat descoberts per primera vegada al Pirineu andorrà. S’ha demostrat, que les espècies vegetals considerades típiques de congesta no viuen ni a les congesteres més innivades ni tampoc a les de més altitud. Això pot permetre, en el cas de desaparèixer progressivament les congestes de menys altitud per un hipotètic canvi climàtic -les situades per sota dels 2540 m-, que les plantes típiques de congestera puguin disposar d'altres congesteres a més altitud per poder-les colonitzar. La colonització, però, dependrà de la quantitat d’hàbitat disponible (sobretot de la presència de matèria orgànica en el sòl) i de les relacions inter-específiques. L’estudi fenològic ha demostrat que determinades espècies adapten la seva fenologia als factors físics locals (com la data de la fosa de la neu o la temperatura acumulada), a fi de permetre maximitzar les probabilitats d’èxit reproductiu. Contràriament, atres espècies no han mostrat cap tipus d’adaptació fenològica. Finalment s’ha avaluat la diversitat funcional a fi de conèixer l’estabilitat de l’hàbitat de congestera i la seva resposta als canvis ambientals (com per ex. respostes en la productivitat o en la resiliència després de canvis sobtats o pertorbacions). Les espècies que dominen en les congesteres situades a menys altitud, amb presència de sòls orgànics i amb menys durada de la coberta de neu, i que d'altra banda són típiques de les pastures d’alta muntanya, s’han trobat relacionades amb valors alts de divergència funcional i amb valors elevats de biomassa aèria. Això s’explicaria per la existència de competència entre espècies. En canvi les espècies de la classe Salicetea herbaceae (considerades com típiques de congesta) s’ha trobat relacionades amb valors alts d’uniformitat funcional, fet que és atribuïble a les condcions físiques més rigoroses (congesteres de més altitud, amb més sòl orgànic i més durada de la coberta de neu) i amb poca competència entre espècies. També s’han mesurat i estudiat els trets biològics funcionals de les espècies més freqüents a fi de caracteritzar la vegetació. L’estudi de la relació entre els trets funcionals i els factors físics a petita escala (ex. data de la fosa de la neu) ha permès avaluar la plasticitat intraespecífica i demostrar que algunes de les espècies més comunes responen significativament als canvis ambientals, en augmentar el nombre d’inflorescències en els indrets de més durada de la coberta de neu.
El cambio climático está afectando a la reducción de la cubierta de nieve, al retroceso de los glaciares y a la desaparición de los neveros en zonas de montaña. En esta Tesis Doctoral se ha realizado la primera cartografía de neveros de Andorra (Pirineos) estudiando las variables físicas que más afectan a su formación y conservación, habiéndose obtenido un mapa que permitirá evaluar la dinámica futura de los mismos. El periodo climático de acumulación de la nieve (enero-abril) se ha identificado como determinante en el número y extensión de los neveros, cuando éste es frío y húmedo. Por lo tanto un aumento de la temperatura o una disminución de la precipitación, en los meses de enero a abril, supondrían una mengua importante en el número y extensión de los neveros. Esta cartografía, que ha permitido incluir hasta 2.540 neveros, debe asentar las bases para el estudio de su vegetación (composición, diversidad biológica, fenología y características funcionales) con el objetivo de relacionarla con los factores ambientales y poder predecir las principales consecuencias del cambio climático. El estudio de la vegetación ha permitido catalogar hasta 85 especies de plantas vasculares, 31 de las cuales son típicas de la vegetación de pastos de alta montaña, y 21 son consideradas típicas de la vegetación de neveros (clase Salicetea herbaceae). Se han identificado 16 briófitos, 2 de los cuales constituyen la primera referencia en el Pirineo andorrano. También se ha evidenciado que las especies consideradas típicas de los neveros no viven en aquellos situados a más altitud ni tampoco en los más innivados. Esta circunstancia permite hipotizar que si progresivamente desaparecen los neveros por un hipotético cambio climático las plantas de los situados a menor altitud dispondrán todavía de terreno a mayor altitud para colonizarlos. Naturalmente, esa colonización dependerá en gran medida de la cantidad de hábitat disponible (sobre todo por la presencia de suelos orgánicos) y de las relaciones sujetas entre las especies. El estudio fenológico indica que algunas de las especies más comunes adaptan su fenología a las variables físicas locales (como fecha de fusión de la nieve o temperatura acumulada), permitiendo maximizar las probabilidades de éxito reproductor. Otras especies no han demostrado ninguna adaptación fenológica. Finalmente se ha evaluado la diversidad funcional para conocer el nivel de estabilidad del hábitat de nevero y su respuesta a los cambios ambientales (como respuestas en la productividad o en la resiliencia después de los cambios o perturbaciones). Las especies identificadas en los neveros, y que son las consideradas típicas de los pastos de alta montaña, se han visto relacionadas con valores elevados de divergencia funcional y con valores altos de biomasa aérea, hecho que se explicaría por la competencia entre especies en los neveros que presentan menos altitud, mas temperatura, presencia de suelos orgánicos y menor duración de la cubierta de nieve. En cambio las especies de la clase Salicetea herbacea, se han visto relacionadas con altos valores de uniformidad funcional, hecho atribuible a las condiciones físicas más severas y a la baja competencia entre especies. También se han medido y estudiado las características funcionales de las especies mas comunes para caracterizar la vegetación. Finalmente el estudio de la relación entre las características funcionales y los factores físicos locales (como la fecha de la fusión de la nieve) han permitido detectar plasticidad intraespecífica de algunas especies, demostrando que responden significativamente a los cambios ambientales, aumentando el número de inflorescencias en los lugares de mayor duración de la cubierta de nieve.
Climate change is contributing to a reduction in snow cover, the rate at which glaciers are receding, and the disappearance of snowbeds in mountains. In this Doctoral Thesis, the snowbeds of Andorra (Pyrenees) were mapped for the first time, which was used to identify the physical factors that have had the greatest affect on the formation and persistance of the snowbeds. That information was used to produce a map that will facilitate assessments of the dynamics of snowbeds in the future. The climatic conditions of the period of snow accumulation (January-April) has a significant effect on the number and extent of snowbeds in the Andorran Pyrenees, but only when the period was cold and wet. An increase in temperature or a reduction in rainfall between January and April, reduces the number and extent of snowbeds. The map, which identified 2.540 snowbeds, has provided a basis from which to study the composition, diversity, phenology, and functional traits of the vegetation in the snowbeds and the influences of environmental factors, and for predicting the most important effects of climate change. In the study, 85 species of vascular plants were documented, 31 of which are typical of mountain pastures and 21 are typical of the vegetation of snowbeds (Class Salicetea herbaceae). In addition, the study identified 16 bryophytes, two of which were documented for the first time in the Andorran Pyrenees. The plant species typical of snowbeds were not present in the snowbeds at the highest elevations or in those that had the longest snow cover; however, if the snowbeds at the lowest elevations disappear progressively, there will be snowbeds at higher elevations that the typical snowbed species can colonize. Colonization will depend largely on the amount of habitat available (especially, the availability of organic soils) and the nature of the relationships between species that become established. Some of the most common species have adapted their phenologies to local physical conditions (such as date of snowmelt and accumulated temperature), which favors their reproductive success. Other species did not exhibit any phenological adaptations. To assess the stability of the snowbeds and the responses to environmental changes (such as changes in productivity or resilience following changes or disturbances), the functional diversity of the snowbeds was evaluated. The species identified in the snowbeds, which are typical of high mountain pastures, were associated with high functional divergence and high biomass, which probably was the result of the competition between species in the snowbeds at low elevations, those exposed to high temperatures that have organic soils, and a relatively short period of snow cover. In contrast, the species of the Salicetea herbaceae class were associated with a high degree of functional uniformity, which suggest severe physical conditions and low competition between species. To characterize the vegetation of the snowbeds, the functional traits of the most common species were assessed. To evaluate intraspecific plasticity, the relationships between the functional and local physical factors (such as date of snowmelt) were evaluated, which demonstrated that the most common species responded significantly to changes in the environment by increasing the number of inflorescences at the sites where snow cover persisted the longest.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Boupoya-Mapikou, Clay-Archange. "Flore et végétation des clairières intraforestières sur sol hydromorphe dans le Parc National de l'Ivindo, Nord-Est Gabon". Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210067.

Testo completo

Abstract (sommario):

L’étude de la flore et de la végétation des clairières sur sol hydromorphe a été menée dans le Parc National de l’Ivindo au Nord-est du Gabon. La méthode phytosociologique de Braun-Blanquet (1932) a été retenue pour la réalisation des relevés au sein des deux principales formations végétales qui composent ce biotope: la prairie et la lisière qui la ceinture. Cent trente trois relevés ont permis de recenser 229 espèces réparties en 175 genres et 72 familles. Les matrices formées à partir de ces relevés et de ces espèces ont été analysées par la méthode Indicator Value (IndVal) ;des analyses canoniques redressées (DCA) et des analyses canoniques des correspondances (CCA) ont servi pour les ordinations. Des analyses de variance (ANOVA) suivies des tests post hoc de Bonferonni ont permis de voir si les valeurs des paramètres environnementaux et structuraux mesurés au sein des différents groupes sont différentes.

La flore globale des clairières est dominée par les Cyperaceae, les Rubiaceae et les Leguminosae-Caesalpinoideae. Cinq espèces (Fuirena stricta subsp. stricta, Pycreus subtrigonus, Pycreus mundtii, Rhynchospora perrieri et Leptochloa coerulecens) sont signalées pour la première fois au Gabon.

Huit groupements sont décrits: 5 pour les prairies et 3 au niveau des lisières. Quatre des groupements des prairies (le groupement pélophyte semi-aquatique à Costus afer et Centotheca lappacea ;le groupement hélophyte semi-aquatique à Pycreus mundtii et Pycreus subtrigonus ;le groupement pélophyte semi-aquatique à Virectaria multiflora et Kyllinga pumila ainsi que le groupement nitrophyte à Tristemma leiocalyx et Bacopa crenata) appartiennent à la classe des Phragmitetea tandis que le dernier (le groupement aquatique à Schoenoplectus mucronatus et Nymphaea heudelotii) se rattache à la classe des Potametea.

Deux des groupements de lisières (le groupement pélophyte pré-forestier à Ludwigia africana et Nephrolepis bisserata; le groupement hygrophyte des forêts marécageuses à Anthocleista schweinfurthii et Uapaca guineensis) appartiennent à la classe des Mitragynetea et le dernier (le groupement nitrophyte pré-forestier marécageux à Leptochloa coerulescens et Echinochloa indica) à celle des Phragmitetea.

L’hydromorphie et la profondeur de la vase ainsi que la fréquentation animale constituent les variables environnementales qui influencent significativement le déterminisme de ces groupements au sein des prairies, alors que ces variables n’ont aucun effet sur les groupements de lisière.

La richesse spécifique varie de 62 à 164 pour les groupements de lisière tandis qu’au sein des prairies, elle varie de 35 à 63. Les indices de diversité moyens pour l’ensemble des groupements des clairières sont 4,4 ± 0,5 (Shannon), 0,07 ± 0,03 (Simpson) et l’équitabilité de Piélou est de 0,78 ± 0,05.

La flore étudié n’est inféodée aux clairières du Gabon, les espèces endémiques guinéo-congolaises sont dominantes au niveau des lisières alors que ce sont les espèces à large distribution qui prédominent dans les prairies. Les géophytes et des thérophytes dominent dans les prairies tandis que les phanérophytes sont dominants dans les lisières. La zoochorie et l’anémochorie constituent les modes de dissémination les plus rencontrés au sein de la flore étudiée.

Mots clés :clairière intraforestière, flore, groupements végétaux, phytosociologie, Gabon.

Abstract

The study of the flora and the vegetation of the swampy clearings on hydromorphic soils were realized in the National Park of Ivindo in north-eastern of Gabon. The phytosociological method of Braun-Blanquet was adopted for the realization of the relevés within the two principal vegetation type which form this biotope: the central meadow and the edge which girdles it. 133 relevés made it possible to count 229 species divided into 175 genera and 72 families. The matrices made starting from these relevés and of these species were analyzed by the method Ind Val; DCA made it possible to obtain groupings; CCA made it possible to evaluate the environmental link between parameter and the vegetation. An analysis of variance (ANOVA) follow-up of the tests post hoc of Bonferonni made it possible to see whether the values measured within the various groups are different.

The flora is dominated by Cyperaceae, Rubiaceae and Leguminosae-Caesalpinoideae. Five species, Fuirena stricta subsp stricta, Pycreus subtrigonus, Pycreus mundtii, Rhynchospora perrieri and Leptochloa coerulescens are announced for the first time to Gabon.

Eight associations are described: 5 for the meadows and 3 on the level of the edges. Four of the associations of the meadows (the pelophyte semi-aquatic association with Costus afer and Centotheca lappacea; the helophyte semi-aquatic association with Pycreus mundtii and Pycreus subtrigonus; the pelophyte semi-aquatic association with Virectaria multiflora and Kyllinga pumila; the nitrophyte association with Tristemma leiocalyx and Bacopa crenata) belong to the class of Phragmitetea while the last (the aquatic association with Schoenoplectus mucronatus and Nymphaea heudelotii) is belong to the class of Potametea .

Two of the associations of edges (the pelophyte pre-forester association with Ludwigia africana and Nephrolepis bisserata; the hygrophyte association of the marshy forests with Anthocleista schweinfurthii and Uapaca guineensis) belong to the class of Mitragynetea and the third (the nitrophyte marshy pre-forester association with Leptochloa coerulescens and Echinochloa indica) to Phragmitetea.

The hydro-morphology and the depth of the mud as well as the animal frequentation constitute the environmental variables which influence the occurrence of these associations within the meadows, whereas they do not have any effect on the association edge.

The species richness varies from 62 to 164 for the association edge while within the meadows it varies from 35 to 63. The average indices of diversity for the whole of the associations of the clearings are 4.4 ± 0.5 (Shannon), 0.07 ± 0.03 (Simpson) while Piélou’s evenness is 0.78 ± 0.05.

The flora is not uniquely linked with the clearings of Gabon, although, on the phytogeographical level, the guineo-congolian endemics are dominant on the level of the edges whereas in fact the species with broad distributions prevail in the meadows. The analysis of the biological types shows the preponderance of the geophytes and the therophytes for the meadows while the edges are largely dominated by phanérophytes. The zoochory and the anemochory constitute the modes of dissemination most met within the studied flora.

Key words: Swampy clearings on hydromorphic soils, flora, association, phytosociology, forest clearings, Gabon.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Gonçalves, Erivelton Tomazzoni. "Padrões de diferenciação florística no extremo sul da Mata Atlântica: influências ambientais e histórica". Universidade do Vale do Rio dos Sinos, 2011. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3453.

Testo completo

Abstract (sommario):

Submitted by CARLA MARIA GOULART DE MORAES (carlagm) on 2015-05-07T14:18:15Z No. of bitstreams: 1 EriveltonTomazzoniGoncalves.pdf: 514129 bytes, checksum: 16d68cb85838c6e25971df9dbe3e7cf1 (MD5)
Made available in DSpace on 2015-05-07T14:18:15Z (GMT). No. of bitstreams: 1 EriveltonTomazzoniGoncalves.pdf: 514129 bytes, checksum: 16d68cb85838c6e25971df9dbe3e7cf1 (MD5) Previous issue date: 2011
Nenhuma
A variação espacial da abundância das espécies pode ser determinada por uma série de causas históricas e ambientais. Visando a identificação de grupos florísticos e a sua relação com um conjunto de variáveis edáficas e climáticas (ambientais), do espaço geográfico (histórico) na estruturação da composição arbórea ao longo de formações ombrófilas e estacionais do extremo sul do bioma Mata Atlântica-Brasil, extraiu-se da literatura dados de composição e abundância da flora arbórea (Dap >9.5 cm), de 52 unidades amostrais com cerca de 1 ha de extensão. As comunidades foram caracterizadas através de sete variáveis climáticas, nove variáveis edáficas, três estruturais, além da diversidade Jost, altitude e suas coordenadas geográficas. Análises de ordenação foram empregadas para síntese dos descritores edafo-climáticos e características estruturais (PCA), na estruturação florística entre as parcelas (NMDS) e posterior correlação com os fatores ambientais. Através de análise de agrupamento hierárquico identificou-se grupos florísticos com utilização de espécies indicadoras, as quais foram classificadas quanto aos seus corredores migratórios. Com o uso do teste G, avaliou-se a independência das rotas históricas de dispersão com a composição das espécies indicadoras dos grupos florísticos. Fatores relacionados ao nicho das espécies, como a temperatura, precipitação total e secundariamente a drenagem, fertilidade e profundidade do solo são consistentes com a distribuição da composição arbórea. Do mesmo modo a longitude configurou-se um forte preditor desta variação florística formando um gradiente ao longo dos corredores de dispersão tropicais, bem como os grupos florísticos obtidos apresentaram espécies indicadoras dependentes dos seus contingentes de origem. Identificou-se um gradiente estrutural de variação de área basal, altura média e densidade entre Florestas Ombrófilas Mistas e Florestas Estacionais, ao contrário da diversidade. Os grupos florestais exibem diferentes graus de separação entre si. As Florestas Estacionais e a Floresta Ombrófila Densa formam um gradiente florístico contínuo ao longo de dois corredores migratórios de modo a consistir um bloco único. A Floresta Ombrófila Mista constitui um grupo dissimilar a estas formações com uma subdivisão marcada por espécies indicadoras exclusivas. Fatores ambientais e históricos são responsáveis tanto pela divisão entre grupos, que podem ser de forma abrupta ou gradativa, quanto pela diferenciação interna destas formações.
The spatial variation of species abundance can be determined by a series of historical and environmental causes. In order to identify floristic groups and their relationship to a set of soil and climatic variables (environmental), the geographic area (historical) in structuring the composition of trees along formations and seasonal rainforests from southern Atlantic forest, Brazil drew from the literature data on the composition and abundance of tree flora (DBH> 9.5 cm) of 52 sample units with about 1 ha in extension. The communities were characterized using seven climate, nine soil and three structural variables, as well as the Jost diversity, altitude and geographic coordinates. Ordination analysis were employed for the synthesis of soil, climatic and structural descriptors (PCA), the floristic structure between plots (NMDS) and subsequent correlation with environmental factors. Through hierarchical cluster analysis identified himself with floristic groups using indicator species, which were classified according to their migratory corridors. By using the G test, we evaluate the independence between the historic routes of dispersion and the composition of indicator species groups. Factors related to the niche of the species, such as temperature, total precipitation, and secondarily drainage, fertility and soil depth, are consistent with the distribution of the composition tree. Likewise the longitude is a strong predictor of floristic variation forming a gradient along the corridors of dispersal tropical flora, and the groups obtained were dependent indicator species of origin of their contingents Unlike the diversity, it was identified a structural gradient of basal area variation, average height and density between Araucaria forest and seasonal forests,. The forestry groups exhibit different degrees of separation between themselves. Seasonal forests and form a dense rain forest floristic gradient along two continuous migration corridors in order to consist a single block. The Araucaria forest is a group dissimilar to these formations with a subdivision marked by unique indicator species. Environmental and historical factors are responsible for both, the division between groups that may be abrupt or gradual, as well as the internal differentiation of these formations.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Abdo, Melissa E. "A Floristic Study of Halmahera, Indonesia Focusing on Palms (Arecaceae) and Their Seed Dispersal". FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3355.

Testo completo

Abstract (sommario):

The dispersal services of frugivores affect plant community assembly, persistence, and gene flow in the short-term, and in the long-term are critical to ensuring that tropical trees and palms can regenerate in disturbed areas and can migrate amidst climate change. Halmahera is the largest Moluccan island within the Wallacea biodiversity hotspot, yet data on its plant and animal distributions and interactions are almost null. I studied the tropical trees and palms of Halmahera and their seed dispersal dynamics. Chapter I explores the palms of the Moluccan islands through field-, herbarium-, and literature- based studies. The results of herbarium specimen collections are presented within a preliminary list of palms for Halmahera’s Aketajawe-Lolobata National Park, and contextualized in a review of regional palm biogeography. Expanding beyond the study of one plant family, Chapter II compiles and examines all the tree and palm taxa of the Moluccan islands in order to infer seed dispersal syndromes for each taxon, resulting in an analysis of over 900 taxa. Zoochory was found in 93% of plant families, and nearly 30% of endemic taxa rely primarily on dispersal by large-bodied frugivores. The role of a hypothesized keystone disperser (the Papuan hornbill, Rhyticeros plicatus ruficollis) is confirmed experimentally to disperse about 10% of Halmahera’s tropical tree and palm taxa. The final chapter encompasses an ex-situ germination trial and a year-long in-situ experimental study that examines the germination and recruitment of three palm species post-ingestion by Papuan hornbills, in four different habitat types representative of Halmahera’s landscape. Palms dispersed by hornbills into disturbed habitats and primary forests resulted in enhanced recruitment, although results varied by habitat and species. Hornbills aid both in forest conservation and recovery/assembly after disturbance. The results of this dissertation provide a foundation for further ecological studies and for enhanced conservation of Halmahera island.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Marques, João Paulo Rodrigues. "Podridão floral dos citros: histopatologia de Colletotrichum acutatum". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-17092012-160523/.

Testo completo

Abstract (sommario):

A podridão floral dos citros (PFC) é uma doença causada pelo fungo Colletotrichum acutatum responsável por causar grandes danos à produção de citros no Brasil. A doença surge apenas em botões florais com 8mm de comprimento ou maiores, levando a formação de lesões alaranjadas nas pétalas, lesões necróticas no estigma, promove a queda prematura dos frutos e a retenção do cálice e pedúnculo, sendo este último sintoma denominado estrelinha. Este trabalho tem por objetivo: observar o modo de penetração do fungo no hospedeiro Citrus sinensis Valência e os estágios posteriores da colonização, verificar se há fatores estruturais e químicos pré-formados que expliquem o porquê do fungo não conseguir infectar botões florais com menos de 8mm, caracterizar anatomicamente o sintoma estrelinha e estigmas lesionados, investigar ultraestruturalmente pétalas inoculadas, analisar se há o estabelecimento de uma infecção quiescente nos tecidos foliares, analisar grãos de pólen após a inoculação in vivo e in vitro com o fungo. Botões florais sadios, pétalas e estigmas com e sem lesões, foram submetidos às técnicas convencionais de microscopia de luz e eletrônica. Folhas e grãos de pólen foram inoculados e analisados. Foi desenvolvida uma nova técnica de coloração para tecidos vegetais infectados por fungos. A resistência dos botões florais menores que 8mm pode estar associada às barreiras químicas e estruturais pré-formadas. O ápice, nesses botões, apresenta papilas entremeadas, cristais de oxalato de cálcio no mesofilo e câmara subestomática e cavidades de óleo localizadas muito próximas umas das outras. Botões com 8mm e 12mm possuem, no ápice, papilas com arranjo frouxo, ausência de cristais e maior distanciamento entre as cavidades de óleo. No ápice da pétala, verificou-se que as células papilosas são osmóforos. No sintoma estrelinha, nota-se sob a região de abscisão do ovário a instalação de um meristema de cicatrização. A lignificação das paredes das células da medula do receptáculo e do pedúnculo floral está associada à retenção destas estruturas na planta. Nas pétalas infectadas, o C. acutatum pode penetrar intra, intercelularmente e via estômato. O fungo pode crescer de modo subcuticular e intramural e coloniza todos os tecidos da pétala. A nova técnica de coloração se mostrou muito útil nas análises histopatológicas. O fungo associa-se aos tecidos vasculares. Acérvulos ocorrem em ambas as faces das pétalas. A cutícula nos estágios mais avançados da lesão apresenta-se alterada, ou seja, ocorre a perda da ornamentação estriada e maior deposição de material lipofílico. A síntese de materiais lipofílicos envolve o retículo endoplasmático liso e rugoso e plastídios. Vesículas provenientes de dictiossomos e de corpos multivesiculares são observadas ao longo da parede celular e estão associadas ao depósito de material lipofílico na cutícula. No estigma lesionado há a formação de uma camada de proteção. O fungo apresenta quimiotropismo e cresce em direção aos grãos de pólen infectando-os 24 horas após a inoculação. Sugere-se que C. acutatum pode utilizar grãos de pólen para a sua dispersão. Após 48 horas da inoculação as folhas apresentam conídios germinados com apressórios.
The postbloom fruit drop (PFD) is a disease caused by Colletotrichum acutatum responsible for causing great damage to citrus crops in Brazil. The disease appears only in flower buds 8 mm in length or greater, leading to orange lesions in petals, necrotic lesions on the stigma, promoting the young fruit drop and the retention of the calyx and peduncle, which is called buttons. In this context, this study aimed to: observe the fungus penetration mode into the host Citrus sinensis \'Valência\' and the later stages of colonization; study the presence of preformed structural and chemical factors to explain why the fungus cannot infect floral buds with less than 8 mm in length; characterize anatomically the symptom \"buttons\" and injured stigmas; investigate the ultrastructural changes in tissues of inoculated petals; analyze whether there is the establishment of a quiescent infection in leaf tissues, analyze pollen grains after inoculation in vivo and in vitro with the fungus. Healthy buds, petals and stigmas with and without lesions, were processed and analyzed using conventional light and electron microscopy techniques. Leaves and pollen grains were also inoculated and analyzed with light microscopy. It was developed a new staining method for fungal-infected plant tissues. The resistance of flower buds smaller than 8mm may be associated with preformed structural and chemical barriers. These buttons display the apex with interspersed papillae, with crystals in mesophyll and substomatic chamber and oil cavities, which are located very close to each other on the abaxial surface. In 8mm and 12mm flower buds, the papilas in the apex become weakly interspaced, the crystals are not observed and there is the increase of the distance between the oil cavities. The papillose cells are osmophores. In the symptom \"button\", it is noted in the abscission of the ovary, an installation of wound meristem. There is also the lignification in the pith of receptacle and pedicel that can be associated with the retention of these structures in the plant. In infected petals, it was found that C. acutatum can penetrate intra and intercelullar or via stomata. The fungus may grow subcuticular and intramural and colonize all tissues of petal. The new staining technique developed has proved very useful for histopathological analysis. The fungus is closely associated with vascular tissues. The acervulli occur on both surfaces of petals. The cuticle in the later stages of the lesion is altered, i.e., there is loss of striated ornamentation and increased deposition of lipophilic material. The synthesis of lipophilic materials involves rough and smooth endoplasmic reticulum and plastids. Vesicles from dictyosomes and multivesicular bodies were observed throughout the cell wall and are associated with the deposit of lipophilic material in the cuticle. There is the formation of protective layer over the stigma damaged area. The fungus shows chemotropism and grows toward the pollen infecting it 24 hours after inoculation. It is suggested that C. acutatum can use pollen grains for dispersal. After 48 hours of inoculation, the leaves have germinated conidia with appressoria.

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "Flora plant"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili