Dissertations / Theses on the topic 'Edaphism'

The wild grass Holcus lanatus is tolerant of a range of edaphic stresses. It possesses genetic adaptations to these conditions which can produce distinct ecotypes and utilises fungal associations to improve stress tolerance. This thesis explores the adaptations and processes employed by two distinct H. lanatus ecotypes from acid bog and limestone quarry soils in response to their soil of origin and the alternate soil type. A de novo RNA-Seq transcriptome was produced for this purpose. Given the role of fungal associations in H. lanatus edaphic adaptation, a novel RNA-Seq assembly, annotation and analysis pipeline was implemented to investigate the root-associated fungal community composition and gene expression response in both soils. Arbuscular mycorrhizal (AM) and non-AM infection was verified using root staining and PCR protocols. Both ecotypes displayed adaptation to their soils of origin with some soil type specific responses indicated. Additionally gene expression in both ecotypes was altered when transplanted to an alternate soil type, although the acid ecotype on lime soil displayed a degree of gene expression similarity to the lime ecotype on lime soil, thereby displaying plasticity in this population. Staining and RNA-Seq analyses detected differences in AM and non-AM infection between soil types, with an ecotype effect detected for non-AM infection on acid soil using root staining. Furthermore the novel RNA-Seq analysis was capable of detecting differences in fungal community composition based on best BLAST alignment, gene expression and gene function, displaying the multifunctional potential of this technique. This thesis identifies putative soil pH adaptations and emphasises the importance of incorporating root fungal community characterisation in studies of stress tolerance between environments whilst introducing a novel RNA-Seq analysis pipeline for studying natural multi-species fungal infections. This technique can incorporate plant-fungal relationships into analyses of stress tolerance adaptations, where the importance of these interactions is increasingly realised.

We sampled seven intact nonriverine wet hardwood forests to establish target ranges for vegetation, soils and hydrology and to examine trends in plant species composition along a wetness gradient. Although quantitative vegetation analysis for this community has been published, broad drainage classes were used to represent a moisture gradient. We investigated trends along a finer-scaled wetness gradient utilizing a novel wetness index that incorporated indicators of saturated soils. Understanding small-scale patterns in plant community composition is useful in planning wetland restoration projects. Although no strong relationship was found between wetness index classes and plant community composition, these data represent the vegetative community supported by soils specific to each wetness class. Absence of this relationship is most likely a result of the dominance of A. rubrum and L. styraciflua in all wetness classes as well as a history of disturbance in each forest and other unknown stochastic variables. For the restorationist hoping to restore a historic nonriverine wet hardwood forest, once known as oak flats, we can suggest guidelines for restoring hydrology to the wetness classes in which we found oaks with high importance.

>Magister Scientiae - MSc<br>The aim of this study is to investigate the edaphic bacterial community dynamics over short (57 days) and long-term (1 year) sampling intervals using an extensive sampling strategy in combination with community fingerprinting by T-RFLP analyses and micro environmental characterization. The short-term study was conducted on three distinct locations in the Namib Desert gravel plains. Soil bacterial communities were found to be more similar within habitats than between habitats, with the differences likely shaped by soil pH. These findings are consistent with the concept of habitat filtering. Investigation of edaphic bacterial communities over 1 year in an 8100 m2 sampling site revealed seasonal patterns of variation in community structure. Soil moisture, phosphorus, potassium and magnesium were identified as significant abiotic drivers of community temporal dynamics. β diversity was found to increase over time, while the environment remained relatively static. These findings support previous observations that desert communities are likely structured by stochastic and deterministic processes. Taken together, these findings advance understanding of temporal variation of edaphic communities in the Namib desert

Adopting nitrogen (N)-fixing legumes into crop rotations is an accessible, ecological practice capable of increasing agricultural sustainability. Nonetheless, in northern Great Plains (NGP) wheat systems, proper water use management and the realization of N benefits are barriers to legumes replacing summer fallow. Legumes should also be able to mitigate legacies of soil organic matter losses from summer fallow. We conducted a participatory field-scale study in north-central Montana, assessing the viability of no-till, early-terminated legume green manures (LGMs) as summer fallow replacements. Soil water and nitrogen were measured to evaluate LGM effects on subsequent wheat crops. Farmers were interviewed to elucidate perspectives and challenges of adopting LGMs. Compared to fallow, LGMs depressed subsequent wheat yields by 6% (0.24 Mg ha -&amp;#185;), and lowered grain protein at sites where wheat was fertilized with N (9 g kg -&amp;#185;); grain protein was increased at unfertilized sites (5 g kg -&amp;#185;). Absent rotational benefits from LGMs were attributed to dry conditions in the LGM year leading to low LGM biomass N and reduced N mineralization potential in soils, rather than soil water limitation to subsequent wheat. Farmers were curious about possible longterm benefits from LGMs, but expressed that the economic viability of LGMs appeared tenuous in the short-term. We also examined attributes and processes in soils from an eight-year-old rotation study containing fallow-wheat, continuous wheat, and legume-inclusive no-till rotations. We examined potentially mineralizable C and N (PMC and PMN), microbial biomass-C and wet aggregate stability (WAS). Nitrogen fertilizer was also added to a duplicate set of soils, and effects on C and N mineralization were evaluated. Legume-inclusive systems generally had higher levels of soil parameters, and had 26-50% greater PMN than wheat-only systems. Systems returning the most crop residue C to the soils had higher WAS regardless of legumes. Nitrogen additions depressed C and N mineralization. Results of these studies suggest that in NGP agroecosystems, LGMs can avoid limiting soil water available to subsequent wheat when terminated early and managed as no-till crops, but that legumes should be viewed as an investment in soil quality which may precipitate rotational N benefits more reliably after three or more appearances in rotation.

Members of the Lasthenia californica species complex show extensive ecological and phenotypic diversity. This thesis investigates patterns of edaphic, physiological, flavonoid, and morphological differentiation within the Lasthenia californica species complex in two distinct studies. In the first study, patterns of ecological and physiological variation along with flavonoid polymorphism and ITS1 species type distribution were characterized. The hypothesis of parallel evolution of edaphically differentiated flavonoid races across lineages of L. californica sensu lato was also examined in this study. We found evidence refuting the predictions of this hypothesis, particularly that flavonoid type and edaphic environments are correlated across the complex. However, when major axes of ecological and physiological variation were characterized within the complex, the greatest amount of edaphic/tissue variation occurred along lines of toxicity, reaffirming prior characterization. In the second study, the basis of the phenotypic differentiation observed between inland and coastal ecotypes of Lasthenia californica sensu stricto was investigated by growing populations of each ecotype in controlled conditions under varying levels of salinity (an important environmental factor differentiating ecotypic environments). Reaction norms of populations were compared under saline conditions to test for evidence of differential fitness between ecotypes (differential salt tolerance) and differences in intrinsic and induced levels of trait expression (e.g. sodium accumulation and succulence). The hypothesis of trade-offs between salt tolerance and growth potentials was also investigated. Under experimental conditions, coastal populations demonstrated uniformly greater salt tolerance than inland populations. We found that most traits showed both intrinsic differentiation and differential responses to salinity, where the extent and direction of trait responses were ecotype specific with little within ecotype differentiation. When comparing growth rate trends between salt tolerant and non-tolerant populations across salinity treatment levels, we found evidence of trade-offs between maximum intrinsic growth rates and investments in salt tolerance.<br>Science, Faculty of<br>Botany, Department of<br>Graduate

A major concern in animal production is the occurrence of hematophagous organisms, as ticks and poultry mites. The control of these organisms is usually done with chemicals. However, this technique is being discouraged in several countries. An alternative measure is biological control. It is known that most mites of the cohort Gamasina (order Mesostigmata) are predators and their diversity and prevalence in places where ticks and poultry mites cause problems are poorly understood. One of the first recommended steps in a biological control program is to determine the fauna where the pest organisms are to be controlled. The objectives of this study were to determine the Gamasina co-occurring with Ixodes ricinus (L.) in pastures in Norway and prospect possible edaphic predatory mites of that group in Brazil to control ticks and poultry mites. In this study, 2,900 Gamasina of 12 families were collected in Norway, co-occurring with I. ricinus. The most abundant families were Parasitidae (46.9%) and Veigaiidae (25.9%), while the most diverse were Laelapidae, Macrochelidae, Parasitidae and Zerconidae, each with five species. Among these mites, a new laelapid species of Cosmolaelaps was found and is here described. In Brazil, 551 gamasines assigned to 11 families were collected and tested for their potential to feed on larvae and eggs of two tick species, Amblyomma sculptum Berlese and Rhipicephalus microplus (Canestrini), and all stages of the red poultry mite, Dermanyssus gallinae (De Geer). The most abundant families were Ologamasidae (25.4%) and Parasitidae (21.1%), while the most diverse (in terms of genera) were Ologamasidae and Laelapidae, with five and four genera, respectively. Of the evaluated predators, only Stratiolaelaps scimitus (Womersley) fed on the larvae of both tick species and all stages of D. gallinae.<br>Uma das principais preocupações ao longo do processo de produção animal é a ocorrência de organismos hematófagos, como carrapatos e piolhinhos. O controle destes organismos usualmente é feito com produtos químicos. Porém, esta técnica de controle vem sendo desencorajada em diversos países. Uma forma alternativa é o controle biológico. Sabe-se que a maioria dos ácaros do grupo Gamasina (ordem Mesostigmata) são de hábito predador, porém sua diversidade e prevalência nos locais em que carrapatos e piolhinhos causam problemas são pouco conhecidas. Um dos primeiros passos recomendados num programa de controle biológico é a determinação da fauna no local onde deseja-se o controle dos organismos praga. Os objetivos deste estudo foram a determinação dos Gamasina que co-ocorrem com Ixodes ricninus (L.) em pastagens na Noruega e a busca por possíveis ácaros predadores edáficos daquele grupo no Brasil, para controle de carrapatos e piolhinhos. No presente estudo, 2900 Gamasina afiliados à 12 famílias foram coletados na Noruega, co-ocorrendo com I. ricinus. As famílias mais numerosas foram Parasitidae (46,9%) e Veigaiidae (25,9%), enquanto que as mais diversas foram Laelapidae, Macrochelidae, Parasitidae e Zerconidae, cada uma com cinco espécies. Dentre estes ácaros, um novo laelapídeo do gênero Cosmolaelaps é descrito da Noruega. No Brasil, foram testados 551 Gamasina afiliados a 11 famílias, incluindo Laelapidae, Macrochelidae, Parasitidae e Veigaiidae, os quais foram testados quanto ao seu potencial em alimentar-se de larvas e ovos dos carrapatos Amblyomma sculptum Berlese e Rhipicephalus microplus (Canestrini), e de todos os estágios do piolhinho-de- galinha, Dermanyssus gallinae (De Geer). As famílias mais abundantes foram Ologamasidae (25,4 %) e Parasitidae (21,1%), enquanto as mais diversas (em termos de gênero) foram Ologamasidae e Laelapidae, com cinco e quatro gêneros, respectivamente. Dos predadores avaliados, apenas Stratiolaelaps scimitus (Womersley) alimentou-se das larvas de ambas espécies de carrapatos e de todos os estágios de desenvolvimento de D. gallinae.

Limestone mining in the San Franicso Mountain Range of west central Utah threatens the survival of a rare endemic species of buckwheat (Eriogonum soredium). This species is an edaphic endemic, only found growing on the outcrops of the Ordovician limestone mines in the area. Eriogonum soredium is a candidate for governmental protection under the Endangered Species Act (ESA). However, a common, widespread buckwheat (Eriogonum shockleyi) appears to be closely related to the narrow endemic. The genetic relatedness of the rare and and common species will greatly influence the decision of United States Fish and Wildlife Service (USFW)of whether or not to list the rare species for governmental protection. This study investiaged the amount of genetic divergence between the two species to facilitate the decision. I found levels of population divergence intermediate between a state of no genetic distinction, and complete genetic divergence. However, the two species fall near the genetic divergence end of the continuum. This situation is not uncommon in plants, and suggests that the two species are currently in the process of speciation. Considering their morphological differences, and the ability of the genus Eriogonum to hybridize, these two species show significant amounts of divergence. These results suggest that the continued treatment of E. soredium as distinct from E. shcokelyi is warranted. The USFW will use the results of this study to aid their decision of whether or not to list E. soredium under the ESA. Should the species be listed for protection under the ESA, limitations to the expansion of limestone mining in the San Francisco Mountain Range will be considered.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-02-08T11:38:37Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5)<br>Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-02-16T11:17:54Z (GMT) No. of bitstreams: 2 Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Made available in DSpace on 2018-02-16T11:17:54Z (GMT). No. of bitstreams: 2 Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-15<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>O objetivo deste trabalho foi estudar a fauna edáfica ocorrente no processo de vermicompostagem dos resíduos de erva-mate, borra de café, estercos bovino, equino e ovino, assim como, analisar química e fisicamente estes materiais. Estes substratos foram armazenados em vasos plásticos com capacidade de 10 litros, em bancadas horizontais em laboratório, utilizando-se um delineamento inteiramente casualizado, com cinco repetições, onde, após um período de estabilização, inoculou-se 150 minhocas da Califórnia (Eisenia foetida) em cada tratamento. Como ferramenta de análise dos dados, utilizou-se o programa estatístico DivEs® para o cálculo dos índices ecológicos de diversidade, dominância, equitabilidade e riqueza de espécies, utilizados para análises da mesofauna edáfica. Foram realizadas avaliações de macronutrientes, relação C/N, carbono orgânico, pH, densidade, umidade, contagem edáfica da mesofauna (ácaros e colêmbolos), da macrofauna (minhocas e casulos) e microorganismos (fungos totais, bactérias degradadoras de celulose e bactérias diazotróficas) além da respiração microbiana. Os resíduos estudados apresentaram resultados distintos entre si. Foi verificado uma superioridade numérica da mesofauna edáfica nos resíduos vegetais quando comparado com os de origem animal, havendo um predomínio de colêmbolos em todos os tratamentos avaliados (95%). Com relação a macrofauna, observou-se um maior número de casulos (n = 323) e minhocas (n = 236) ao final do processo de vermicompostagem, no esterco ovino. Ao longo da execução do experimento notou-se que somente no tratamento esterco bovino houve uma diminuição no desenvolvimento de bactérias degradadoras de celulose (de 6,6 x 1011 para 2,3 x 109 ), já para as bactérias diazotróficas, apenas no tratamento esterco equino ocorreu um aumento na sua população (de 6,0 x 103 para 9,5 x 107 ). Fungos totais mantiveram uma distribuição homogênea no decorrer das avaliações em todas as unidades experimentais. Na totalidade das amostras houve uma redução da respiração microbiana durante o processo de vermicompostagem, devido a maturação dos resíduos orgânicos. Observou-se uma diminuição da relação C/N, com destaque para os resíduos vegetais que apresentaram os maiores valores da mesma, entretanto, nestes resíduos foram verificados as menores concentrações dos macronutrientes P, K e Mg. Com exceção do esterco equino, o pH ajustou-se para valores recomendáveis ao final do experimento em todos os substratos. Os índices ecológicos de diversidade e equitabilidade mostraram um predomínio de organismos no esterco ovino. Diante dos resultados obtidos neste estudo, pode-se sugerir a utilização destes resíduos para a vermicompostagem, e recomendar o uso de seus vermicompostos como adubo orgânico com precauções.<br>The objective of this work was to study the edaphic fauna occurring in the vermicompost process of the residues of herb-checkmate, coffee drag, bovine, equine and ovine manure, as well as to analyze chemically and physically these materials. These substrates were stored in 10 liter plastic plots in horizontal laboratory benches, using a completely randomized design with five replications, where, after a stabilization period, 150 California worms (Eisenia foetida) in each treatment. As a tool for data analysis, the statistical software DivEs® were used to calculate the ecological indexes of diversity, dominance, equitability and species richness, used for analysis of the edaphic mesofauna. In this study different evaluations were made such as: macronutrients, C/N ratio, organic carbon, pH, density, humidity, counting of the edaphic mesofauna (mites and collembolans), macrofauna (worms and cocoons) and microorganisms (total fungi, cellulose-degrading bacteria and diazotrophic bacteria) and microbial respiration. The residues studied presented different results among themselves. It was verified a numerical superiority of the edaphic mesofauna in the vegetal residues when compared with the ones of animal origin, being a predominance of collembolans in all the evaluated treatments (n = 121864). With regard to macrofauna, a larger number of cocoons (n = 323) and earthworms (n = 236) were observed at the end of the vermicompost process in ovine manure. During the execution of the experiment it was noticed that only in the bovine manure treatment there was a decrease in the development of cellulose degrading bacteria (from 6.6 x 1011 to 2.3 x 109 ), already for the diazotrophic bacteria, only in the treatment equine manure occurred an increase in its population (from 6.0 x 103 to 9.5 x 107 ). Total fungi maintained a homogeneous distribution throughout the evaluations in all the experimental units. In all the samples there was a reduction of the microbial respiration during the vermicompost process due to the maturation of the organic residues. It was observed a decrease in the C/N ratio, with emphasis on the vegetable residues that presented the highest values of the same, however, in these residues were verified the lowest concentrations of the macronutrients P, K and Mg. With the exception of equine manure, the pH adjusted to values recommended at the end of the experiment on all substrates. The ecological indexes of diversity and equitability showed a predominance of organisms in ovine manure. Considering the results obtained in this study, we can suggest the use of these residues for vermicomposting, and recommend the use of their vermicompost as an organic fertilizer with the precautions.

Orientador: Raphael de Campos Castilho<br>Resumo: As pesquisas sobre a acarofauna edáfica nos diversos biomas do território brasileiro são incipientes, sendo que em algumas localidades não se têm estudos, como no estado de Pernambuco. Um dos grupos mais encontrados em ambiente edáfico é o Gamasina (Mesostigmata), conhecidos pelo potencial como inimigos naturais de diversas pragas e parasitos. O objetivo do presente estudo foi determinar a diversidade e flutuação populacional de ácaros edáficos, com ênfase nos Gamasina, de uma região de Caatinga no Vale do São Francisco (Petrolina-PE), comparando a diversidade, distribuição e abundância desses organismos em solos de mata nativa e de cultivos de manga, uva e cebola. Amostras de solo foram coletadas mensalmente durante um ano, em quatro áreas diferentes da Caatinga: uma mata de vegetação natural, um cultivo de manga, um cultivo de uva e um cultivo de cebola. Em cada uma dessas áreas foram escolhidos 16 pontos amostrais aleatoriamente. Em cada ponto foi recolhidafoi recolhida uma amostra de solo (0-5 cm de profundidade). Os Gamasina encontrados foram divididos em morfoespécies e identificados, sempre que possível, até o nível de espécie. Durante todo o estudo foram coletados 1.151 ácaros (adultos e imaturos) de 10 famílias de Gamasina. No total de famílias encontradas, foram identificados 18 gêneros e 30 morfoespécies de Gamasina, sendo duas destas novas para a ciência. As espécies mais abundantes foram Multidentorhodacarus squamosus e Protogamasellus mica. Do total de ácaros co... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The researches about edaphic acarofauna in different biomes of the Brazilian territory are incipient, being that in some localities, as Pernambuco State,there are no studies. One of the groups most found in edaphic environment is Gamasina (Mesostigmata), known for their potential as natural enemies of various pests and parasites. The objective of the present study was to determine the diversity and population fluctuation of edaphic mites, with emphasis on the Gamasina, from a Caatinga region in the São Francisco Valley (Petrolina-PE), comparing diversity, distribution and abundance of these organisms in soils of native forest, mango, grape and onion crops. Soil samples were collected monthly during one year in four different selected areas in the Caatinga: a natural forest vegetation, a mango cultivation, a grape cultivation and an onion cultivation. In each one of these areas, 16 randomly sample points were selected. At each point a soil sample (0-5 cm depth) was collected. The Gamasina found were divided into morphospecies and identified, where possible, up to the species level. Throughout the study, 1151 mites (adult and immature) were collected from 10 families of Gamasina. In the total of families found, 18 genera and 30 morphospecies of Gamasina were identified, two of which were new to science. The most abundant species were Multidentorhodacarus squamosus and Protogamasellus mica. Of the total number of mites collected, about 47% were found in the area with grape culti... (Complete abstract click electronic access below)<br>Mestre

To determine how Pacific Northwest prairies are influenced by local site factors versus. regional climate, we studied the reproduction, plant size, and density of sixteen natural populations of four perennial forb species native to Pacific Northwest prairies: Ranunculus austro-oreganus, Sidalcea malviflora spp. virgata, Microseris laciniata, and Eriophyllum lanatum. These populations were distributed along a 700 kilometer latitudinal gradient from southern Oregon to Whidbey Island, Washington. We found significant differences in plant size and reproduction among populations for all species, but correlations among edaphic and climate variables and plant size and reproduction were weak. Instead, density was more strongly correlated with both edaphic and climate variables, suggesting that this is a better indicator of long-term demographic processes. Although a few factors are important across species (e.g., nutrient availability and minimum temperature), response is idiosyncratic at the individual species level in Pacific Northwest prairies.

Orientador: Raphael de Campos Castilho<br>Resumo: Atualmente há pouco conhecimento sobre o impacto dos sistemas de cultivo sobre a diversidade da fauna edáfica, incluindo dos ácaros predadores Gamasina (Mesostigmata). O primeiro passo para entender a influência das práticas agrícolas na biota do solo é justamente conhecer a diversidade de organismos destes ambientes. Sendo assim, o objetivo desta pesquisa foi conhecer, determinar e comparar a diversidade de ácaros Gamasina (Mesostigmata) edáficos em plantios de soja em sistema de plantio direto e em sistema de cultivo integração lavoura, pecuária e floresta (ILPF), localizados no bioma Cerrado, no estado do Mato Grosso. Amostras de folhedo e solo foram coletadas em cultivos de soja em uma área em sistema de plantio direto com apenas um cultura (SPD) e em uma área área com sistema ILPF, também em plantio direto. Os resultados indicaram que a maior abundância de ácaros foi encontrada em sistema SPD em relação ao sistema ILPF. A maior abundância encontrada nas amostras de solos nos dois sistemas de cultivo foi da família Rhodacaridae, enquanto para as amostras de folhedo foram as famílias Laelapidae e Macrochelidae. Observou-se que o fator floresta do sistema ILPF não apresentou diferencial em relação ao sistema SPD. Tal fato pode ter ocorrido devido as mesmas atividades de tratos culturais ocorrerem em ambas as áreas, além da possibilidade de o tempo de implantação de ILPF ser curto. A espécie Gamasellodes sp. nov. foi encontrada no estudo e descrita, sendo disponibilizada a c... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Currently knowledge about the impact of cropping systems on the diversity of edaphic fauna is incipient, including Gamasina (Mesostigmata) predatory mites. The first step to understand the influence of agricultural practices on soil biota is to know the diversity of organisms in these environments. Thus, the objective of this research was to know, determine and compare the diversity of edaphic Gamasina (Mesostigmata) mites in soybean crops under no-tillage system and in crop, livestock and forest integration system (ILPF), in the Cerrado biome, in the state of Mato Grosso. Litter and soil samples were collected from soybean crops in an area under no-tillage system (SPD) and in an area with ILPF system, also under no-tillage. The results indicated that the higher abundance of mites was found in SPD in relation to ILPF. The highest abundance of edaphic mites found on soil samples in both cropping systems was from the Rhodacaridae family, while the litter samples were the families Laelapidae and Macrochelidae. It was observed that the forest factor of the integrated crop, livestock and forestry system did not differ in relation to the SPD. This fact could have occurred due to the same crops activities occurring in both areas, besides the possibility of the time of implantation of the ILPF system to be short. In addition, a new species has been found. The species Gamasellodes sp. nov was found in the study and described, and the identification key for species in the world of Gama... (Complete abstract click electronic access below)<br>Mestre

Natural forests are characterised by great vegetation diversity and create habitats for a major part of Earth’s terrestrial organisms. Plantation forests, which are mainly composed of a few genera of fast-growing trees, constitute an increasing fraction of global forests, but they only partly compensate for loss of area, habitat and ecological functions in natural forests. Plantation forests established near natural forests can be expected to serve as buffers, but they seem to be relatively poor in invertebrate species and it is not clear why. This bachelor’s degree project aimed at establishing the ecological and edaphic factors that correlate with soil invertebrate diversity in dry upland forests and surrounding plantation forests in eastern Africa. Some aspects of the above-ground vegetation heterogeneity were investigated since this was assumed to influence the heterogeneity of the soil environment, which is considered as critical for soil biodiversity. The obtained knowledge may be valuable in conservation activities in East African forests, which are threatened by destruction, fragmentation and exotic species. The study area was Karura Forest, a dry upland forest in Nairobi, Kenya. Three different sites were investigated; a natural forest site characterized by the indigenous tree species Brachylaena huillensis and Croton megalocarpus, and two different plantation forest sites, characterized by the exotic species Cupressus lusitanica and Eucalyptus paniculata, respectively. For each forest type, six plots were visited. Soil invertebrates were extracted from collected soil and litter samples by sieving and Berlese-Tullgren funnels. The invertebrates were identified, and the taxonomic diversity calculated at the order level. The ecological and edaphic factors, measured or calculated for each plot, were tree species diversity, ratio of exotic tree species, vertical structure of trees, vegetation cover, vegetation density, litter quality, soil pH, soil temperature and soil moisture. One-way ANOVA was used to compare soil invertebrate diversity and other variables between different forest types. Akaike’s Information Criterion and Multiple Linear Regression were used to establish linear models with variables that could explain measured variations of the diversity. There was some evidence for higher soil invertebrate diversity in natural forests than in surrounding plantation forests. The abundance of soil invertebrates was also clearly higher in natural forests, which indicates that natural forests are more important than plantation forests for conservation of soil invertebrate populations. Soil invertebrate diversity (in terms of number of orders present) was found to be influenced by forest type and litter quality. The diversity was higher at places with high amounts of coarse litter, which here is considered as more heterogenous than fine litter. The dependence on forest type was partly a consequence of differences in soil pH since Eucalyptus trees lower soil pH and thereby also soil biodiversity. No relation to heterogeneity of above-ground vegetation was found. For future conservation activities in Karura Forest Reserve it is recommended to continue removing exotic plant species and replanting indigenous trees, to prioritize the removal of Eucalyptus trees before Cypress trees, to only remove a few trees at a time and to establish ground vegetation when doing so.

Soil-water interactions with nutrients are central to understanding constraints to rice production in the rainfed lowlands. Proper identification of the nature of these constraints may lead to increasing farm productivity through the identification and use of effective soil amendments and an appropriate application of fertilisers. This thesis has made a significant contribution to the understanding of soil water x phosphorus interactions in the rainfed lowland rice ecosystems, by a series of experiments on two rainfed lowland soils of southeast Cambodia. The most common physical and chemical properties of the two Cambodian rainfed soils: the Black clay soil (Kandic Plinthaquult) and the Sandy soil (Plinthaquult) were determined. The soils were strongly acidic (pH, CaCl2 = 4.0), low in total N (<2.0 g/kg), Olsen-extractable P (<2.5 mg/kg), organic carbon (<15 g/kg), effective cation exchange capacity (ECEC<4.0 cmolc/kg), and they possessed high Al saturation of the ECEC (70-80 %). Changes in their chemical properties caused by flooding and temporary loss of soil-water saturation, and the consequences of these changes for the growth and grain yield of rice (Oryza sativa L.) were also examined. It was concluded from a field experiment in southeast Cambodia that low rice yields and a weak response to the application of inorganic fertiliser were most likely due to a temporary loss of soil-water saturation restricting nutrient availability and uptake by the rice plants. In subsequent glasshouse and field experiments, the P uptake and growth of rice plants grown under fluctuating soil-water regimes were closely related to changes in soil pH and Eh. Changes in soil pH and Eh corresponded closely to varied soil-water regimes. This controlled P uptake and shoot dry matter yields, presumably by affecting P availability. Continued or temporary loss of soil-water saturation decreased rice growth significantly from that in the continuously flooded soils. This was related to substantial decreases in P uptake, apparently caused by decreased P availability resulting from oxidation of soil after a loss of soil-water saturation. The decreases of shoot dry matter under a temporary loss of soil-water saturation were associated with two mechanisms at least. Firstly, when the soils were subjected to a loss of soil-water saturation the reactions of phosphates with Fe released during prior flooding resulted in a decline in the availability of native and added P fertiliser. Secondly, during the loss of soil-water saturation, exchangeable Al levels were high enough to account for the decrease in P uptake by the rice plants. The addition of straw ameliorated the effects of a temporary loss of soil­water saturation on growth of rice because it stimulated soil reduction and lessened changes in soil pH and Eh. It resulted in increased shoot dry matter yields through increased P uptake by the rice plants. The beneficial effects of straw were attributed in part to the direct addition of P, N or K to the soils. In addition, the stronger soil reduction it induced restricted the formation of Fe bound phosphates and increased the plant-availability of P. In the rainfed lowlands, fluctuations in soil-water regimes vary greatly in timing, intensity, and duration. The availability of P is expected to vary correspondingly. More information is needed to manage the effects of fluctuating soil-water regimes on P supply to increase productivity over the range of soil types, cultural practices and seasonal conditions found in rainfed lowland ecosystems.

Contrary to the other forest ecosystems in the Democratic Republic of Congo (D.R. Congo), semi-deciduous forests have so far attracted little attention and studies regarding their ecological aspects remain sketchy. Yet semi-deciduous forests are among the most important non-flooded ecosystems in the Congo Basin and their importance is high, both ecologically and economically. They are home to a variety of species, some of them being exploited for timber by forest companies acting in the region. There is a constant need to focus on their composition and diversity, and to understand factors shaping their communities.<p>Using a sampling method broadly inspired from the synusial phytosociology approach, we examined plant communities within each of the forest layers composing the overstorey (canopy and emergent trees) and the understorey (shrub and herbaceous layers). <p>The role of edaphic heterogeneity on plant communities in the considered semi-deciduous forests was examined. We mainly focused on:<p>- Floristic parameters within these ecosystems;<p>- Spatial structure of edaphic variables;<p>- Species responses to edaphic heterogeneity;<p>- Distance decay in the considered ecosystems;<p>- Phylogenetic patterns within plant communities.<p>Some of the species found in the considered semi-deciduous forests are more related to a type of soil than another, defining some “edaphic specialists” species while many others can be considered “generalists”. Spatial distance effect in the considered plant communities is marked by a decrease of floristic similarity with the geographical distance and all the forest layers showed a pattern of spatial phylogenetic clustering meaning that species cohabiting within a same plot are more related than species from distant plots.<p><br>Doctorat en Sciences<br>info:eu-repo/semantics/nonPublished

The Styx Mill Reserve is located in Belfast, Christchurch and is managed by the Christchurch City Council. Who aim to re-establish indigenous vegetation to large proportions of the area. These efforts have been successful in some sections of the Reserve; but large areas of the Reserve remain in grass and other weeds. The purpose of this investigation was to evaluate the presence of 5 hypothesised edaphic1 zones in a 10 ha study area, with a future aim of matching establishment practices to these edaphic sites. Findings indicated that all zones have significantly different vegetation and soil characteristics. Consequentially methods of native re-vegetation must be different in each zone if successful re-establishment of native species is to occur. Based on confirmed edaphic zones and client input, a site matched management plan and species list for one zone was developed. This aimed to increase the health and survival rates of plantings. Site modification followed techniques used at sites with similar conditions that have had successes in establishing woody vegetation. The effect of hydrogel on heath and survival levels was also trialled. To assess species suitability, five species were selected based on their abilities to survive the site conditions. Due to a combination of frost damage and ungulate browse, only totara survived and demonstrated good health scores. The frost factor is difficult to mitigate, hence species affected severely by frost are not recommended. The browse issue is easier to mitigate and it is felt that the two species heavily browsed, but not frosted are likely to be suitable. This resulted in ribbonwood, totara and kōhūhū being recommended. The time period did not allow assessment of the hydrogel treatment. Insufficient trial numbers exist to continue trials assessing future growth and survival rates over a longer time scale.

Fabaceae is the second most speciose plant family in the Core Cape Subregion (CCR) of South Africa, a Mediterranean type ecosystem, with mostly nutrient-poor soils. A majority of the legumes occurring in this region belong to the predominantly nitrogen-fixing subfamily Papilionoideae and they employ a variety of strategies for nutrient acquisition. However, legumes are neither uniformly nor randomly distributed in the CCR landscape. Instead, distinct legume species assemblages tend to occupy particular habitats within the landscape. The drivers of this distribution pattern are yet to be determined. In this thesis, it was hypothesized that edaphic factors (soil chemical and physical characteristics) and the distribution of rhizobia have influenced legume distributions in the CCR landscape. The influence of edaphic factors on the distribution of legume species assemblages in the Cape Peninsula (a microcosm of the CCR) is the subject of the second chapter of the thesis. It was hypothesized that the composition of legume species assemblages is correlated with soil physical and chemical properties and that the interaction of Phosphorus (P) and the three cations that often bind P, i.e. Aluminium, Calcium and Iron, making it unavailable to plants, drive legume species assemblages in the landscape. Soils from 27 legume sites, spanning all major soil types of the Cape Peninsula, were analysed for 31 chemical and physical properties. Surveys of legume species present at each site were conducted to generate a presence/absence matrix. Canonical correspondence analysis was used to test for a correlation between legume species composition and edaphic factors. The strength of the association between legume species composition and site groupings based on edaphic properties was assessed using indicator species analysis. A significant correlation between edaphic factors and species composition was found and the key edaphic parameters driving the relationship were clay content, iron (Fe), potassium (K), sulphur (S) and zinc (Zn). Indicator species, characteristic of the various edaphic habitats were also identified. These findings indicate that distinct edaphic habitats are occupied by discrete legume species assemblages, implying a significant influence of edaphic factors on the legume distributions. Chapter three of the thesis sought to determine if the ecological parameters; altitude, pH and soil type influence the distribution of the two main rhizobial genera (Burkholderia and Mesorhizobium) that nodulate various legumes of the CCR, and to determine the diversity and phylogenetic position of rhizobia that associate with the narrowly distributed and rare Indigofera superba in the CCR. The first objective was pursued through molecular characterisation of rhizobial strains isolated from nodules of legume species collected in the field across the Cape Peninsula. DNA sequences for 16S rRNA, recA and nodA were combined with data from a previous study that sampled broadly within the CCR and phylogenetic analyses were conducted. Tests for phylogenetic signals for the three ecological parameters were conducted, using the D statistic for soil type and Pagel’s λ for altitude and pH. These analyses were used to test the hypothesis that closely related species occupy similar habitats with respect to each of the three ecological parameters. For the study of rhizobial symbionts of Indigofera superba, field nodules were sampled from multiple populations across its distribution range and a phylogeny of its symbionts was reconstructed in a matrix that included symbionts of diverse legumes from different habitats within the CCR. The results showed that Burkholderia is restricted to acidic habitats, while Mesorhizobium occurs in both acidic and alkaline habitats. Additionally, both rhizobial genera showed significant phylogenetic clustering for pH and most soil types. However, none of the genera showed a phylogenetic structure with respect to altitude. These findings indicate that pH and soil type influence the distribution of rhizobia in the CCR. Implications of these findings for the distribution of legumes in the landscape are discussed. For the narrowly distributed I. superba, the results showed that it associates with diverse strains within the genus Burkholderia and such strains are not phylogenetically distinct from strains isolated from localities outside its distribution range. These findings lead to the hypothesis that I. superba does not exhibit rhizobia specificity at the intrageneric level. Testing of this hypothesis through analysis of its nodulation capability on soils from outside its distribution range is recommended. The fourth chapter of the thesis determined the extent of horizontal gene transfer among rhizobial genera in the Core Cape Subregion (CCR) of South Africa and reconstructed the ancestral symbionts of the legumes. Phylogenies of two chromosomal genes (16S rRNA and recA) and one nodulation gene (nodA) of rhizobia, isolated from diverse legumes in the CCR, were reconstructed using Bayesian and Maximum Likelihood techniques. A cophylogenetic analysis was used to test for congruence between the chromosomal and the nodA phylogenies. Five genera of rhizobia (Bradyrhizobium, Burkholderia, Ensifer, Mesorhizobium and Rhizobium) were studied. A phylogeny of the legumes was reconstructed from matK and rbcL DNA sequences and it was used to reconstruct their ancestral rhizobia, using Bayesian methods. The chromosomal phylogeny of the rhizobia was mostly incongruent with that of nodA, indicating potential horizontal inheritance of the latter. The nodA genes of Burkholderia, Mesorhizobium and Rhizobium had different evolutionary histories from their counterparts in other parts of the globe. Burkholderia was reconstructed as the ancestral symbionts of the CCR legumes. Evidence of co-diversification between the legumes and their symbionts was observed and this highlights a potential role of the legume-rhizobia interaction to the high diversity of legumes in the CCR. Finally, the availability of compatible rhizobia and their competitive ability are discussed as possible drivers for the lack of shared legumes between the CCR’s Fynbos biome and the Kwongan of Australia. Overall, the study shows that edaphic factors and biotic interactions (rhizobia) have significant influence on the distribution of legumes in the Cape Peninsula and the larger Core Cape Subregion of southern Africa. These findings are consistent with the theory that edaphic factors and biotic interactions have a strong influence on species distributions at local and site spatial scales.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-10-04T20:06:24Z No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5)<br>Made available in DSpace on 2017-10-04T20:06:24Z (GMT). No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5) Previous issue date: 2017-03-06<br>Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão<br>ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of Maranhão state, Brazil. It were installed 130 pitfall traps in five areas with different management (millet, soybean, maize, eucalyptus, and pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. The geostatistical analysis was evaluated by a semivariogram, adjusted to a geostatistical, spherical, gaussian or exponential model. The multifractality was analyzed by the current method, in successive segments of different sizes of 2k , k=0 a k= 7 in the range of q = +10 to q = -10. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability. For the areas of millet, maize, eucalyptus, anthropized Cerrado and pasture the Shanon diversity index obtained pure nugget effect. For the areas of millet, maize, anthropized Cerrado and pasture, the total diversity index was adjusted to the gaussian model. Only for the areas of soybean and pasture the staggered semivariograms showed similarity in the spatial variability of indexes, indicating that they behave similarly. The multifractality generated generalized dimension, D0, for all the indexes in the millet area, with invariant values, D0 = 1.000 ± 0.000. The singularity spectra were curves in concave parables with greater or smaller asymmetry for all areas sampled. In general, the fauna of soil presented spatial variability and multifractal parameters.<br>ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of the State of Maranhão, Brazil. Were installed 130 pitfall traps in five areas with different management (Millet, Soybean, Maize, Eucalyptus, and Pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability.

Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010.<br>ENGLISH ABSTRACT: Cabernet Sauvignon is the most planted red cultivar in South Africa and the second most planted red cultivar in the Olifants River region. The cultivar is prone to vigorous growth with low yields. Excessive irrigation could accentuate these cultivar characteristics. Considering the foregoing, the aim of the study was to describe how Cabernet Sauvignon will react to climate, soil type (texture) and irrigation within the Lower Olifants River wine region to enable growers to make the right decisions regarding long term as well as short term cultivation practices. This study is part of a project carried out by the ARC Infruitec-Nietvoorbij at Stellenbosch to determine the effects of soil type and atmospheric conditions on yield and wine quality of Cabernet Sauvignon in different grape growing regions of South Africa. Similar studies are being carried out in the Orange River, Stellenbosch and Swartland regions of South Africa. The Lower Olifants River region could be divided into three climatic regions. Furthermore, two climatic regions is evident regarding the formation of grape wine colour and aromas. Proximity to the Atlantic Ocean would play an important role in a cultivar establishment policy. The variation in stem water potential (ΨS) could be related to soil water status expressed in terms of matric potential (ΨM). In the case of sandy soils, ΨS decreased substantially more as the ΨM decreased compared to the sandy loam soils. The reason could be that the unsaturated hydraulic conductivity in sandy soils decreased more rapidly as the ΨM decreased compared to the heavier soils. Thus could explain why the grapevines in the sandy soils experienced more water stress than the ones in the sandy loam soils at a given ΨM. Climate had a strong influence on grapevine water status with grapevines nearer to the ocean experiencing less water stress compared to the ones further inland. This was especially true for grapevines in the sandy soils. Vegetative growth and yield of grapevines in the sandy soils were more sensitive to water deficits compared to the ones in the sandy loam soils. For deficit irrigated grapevines in the sandy soils, vegetative growth and yield decreased by ca. 30% when ca. 55% less water was applied from flowering to harvest. Yield reduction were ca. 15% with no or very little influence on vegetative growth with ca. 80% reduction in water applied from flowering to harvest for grapevines in the sandy loam soils. The influence of soil texture on wine quality and style were evident under intensive irrigation as well as over different climatic regions. Overall sensorial potential wine quality of grapevines in sandy soils tended to be higher compared to the ones in the sandy loam soils. Deficit irrigation tended to increase wine colour intensity, irrespective of soil texture. Furthermore, deficit irrigation in sandy loam soils tended to increase wine fullness and the berry characteristics of the wine. Berry characteristics of wines from the sandy soils tended to be higher compared to the ones from the sandy loam soils. Too severe water deficits in sandy soils could be detrimental to wine quality. Climate tended to have an influence on wine style of grapevines in the sandy soils with wines produced further away from the ocean tended to have higher berry characteristics. Irrigation management could be a powerful tool to manipulate the grapevine in sandy soils. For grapevines the sandy loam soils in addition to regulated deficit irrigation, additional canopy management practices could be needed to improve wine quality.<br>AFRIKAANSE OPSOMMING: Cabernet Sauvignon is die mees aangeplante rooidruif kultivar in die Suid-Afrikaanse wynbedryf. In die Olifantsriver streek is dit naas Shiraz, die tweede mees aangeplante rooidruif kultivar. Cabernet Sauvignon is bekend as ‘n groeikragtige skaamdraer. Indien oorbesproei word, kan hierdie potensiële nadelige eienskappe nog meer na vore tree. Die doel van die studie is om die invloed van die klimaat, grond en besproeiing op Cabernet Sauvignon se vegetatiewe groei, produksie en wyngehalte in die Benede Olifantsrivier streek te bepaal. Hierdie inligting kan produsente help om ingeligte kortsowel as langtermyn besluite te maak rakende die verbouing van Cabernet Sauvignon. Hierdie studie vorm deel van ‘n breër studie in die Suid-Afrikaanse wynbedryf, gedryf deur die Landbou Navorsingsraad (LNR) Infruitec-Nietvoorbij, Stellenbosch om die invloed van atmosferiese toestande en grond op die produksie en wyngehalte van Cabernet Sauvignon te bepaal. Soortgelyke projekte word uitgevoer in die Oranjerivier, Stellenbosch en Swartland wynstreke. Die Benede Olifantsrivier streek kan verdeel word in drie klimaatstreke op grond van temperatuurdata. In terme van die ontwikkeling van druifkleur en aromas, kan die streek verdeel word in twee klimaatstreke. Die afstand vanaf die Atlantiese Oseaan kan ‘n belangrike rol speel in die ontwikkeling van ‘n kultivarriglynplan vir die streek. Grondwaterstatus, uitgedruk as die matrikspotensiaal (ΨM), kan aanleiding gee tot variasie in middag blaarwaterpotensiaal (ΨS) lesings. Die ΨS van die sand gronde verlaag vinniger soos die ΨM verlaag invergelyke met die sandleem gronde. Dit kan moontlik wees as gevolg van die verskil in die grond onversadigde hidroliese konduktiwiteit. Sand gronde se hidroliese konduktiwiteit verlaag vinniger soos die ΨM verlaag, invergelyke met sandleem gronde. Dit verklaar waarom wingerde in sand gronde by dieselfde ΨM, meer waterspanning ondervind as wingerde in sandleem gronde. Klimaat het ‘n invloed op die waterstatus van die wingerdstok. Wingerde nader aan die see het minder waterspanning ondervind invergelyke met wingerde wat verder in die binneland geleë is. Dit was veral die geval met wingerde in die sand gronde. Vegetatiewe groei en produksie van wingerde in die sand gronde is meer sensitief vir waterspanning as wingerde in die sandleem gronde. Tekortbesproeiing in die sand gronde het die groei asook produksie met ongeveer 30% verlaag deur ongeveer 55% minder water toe te dien vanaf blom tot oes. In teenstelling daarmee is die produksie van wingerde in die sandleem gronde met ongeveer 15% verlaag met geen tot baie min verlaging in die groeikrag. Ongeveer 80% minder water is toegedien vanaf blom tot oes. Grondtekstuur kan wyngehalte en -styl beïnvloed ten spyte van intensiewe besproeiing en klimaatsverskille. Sensoriese potensiële wyngehalte van wingerde in die sand gronde was beter invergelyke met dié van die sandleem gronde. Die wyne vanaf die sand gronde het ook geneig om oor meer bessie intensiteit te beskik as wyne vanaf die sandleem gronde. Tekortbesproeiing neig om die wynkleur intensiteit te verhoog, ongeag van grondtekstuur. Tekortbesproeiing in die sandleem gronde kan ook die volheid van die wyne verbeter, asook die bessie intensiteit van die wyn verhoog. Te hoë waterspanning in die sand gronde kan wyngehalte nadelig beïnvloed. Klimaat kan ook die wynstyl vanaf sand gronde beïnvloed met wyne verder vanaf die see wat oor meer bessie intensiteit beskik as wyne nader aan die see. Beheerde tekortbesproeiing kan as ‘n kragtige hulpmiddel gebruik word om wingerde in die sand gronde te manipuleer. Vir wingerde in die sandleem gronde, addisioneel tot beheerde tekortbesproeiing en normale loofbestuurspraktyke, kan ekstra loofbestuurspraktyke bv. die verwydering van sylootlote, dalk nodig wees om wyngehalte te verbeter.

En raison de la croissance importante de la demande des consommateurs pour la framboise, la production a connu un essor considérable au cours des dernières décennies. L’augmentation du rendement est une précoccupation des producteurs qui doivent répondre à cette demande. De plus, la croissance des plants de framboise peut être limitée et leur physiologie peut être affectée par des facteurs abiotiques (lumière, température, déficit de pression de vapeur). Dans ce contexte, cette thèse a étudié : 1) les méthodes de culture (la culture en plein champ versus la culture hors-sol, les régimes de fertigation, les substrats et les méthodes de propagation); 2) les effets de l’environnement (e.g. lumière) sur la photosynthèse, la conductance hydraulique du plant et des feuilles ainsi que le rendement en fruits. Notre hypothèse générale en ce sens étant que la surface foliaire élevée des cultures hors-sol de framboisiers pourrait limiter leur rendement en fruit dû à un ombragement excessif des zones fruitières et/ou à un manquement de la capacité hydraulique à rencontrer la demande évaporative. De plus, l’effet de la température foliaire et du déficit de pression de vapeur entre les feuilles et l’atmosphère (VPDleaf) sur la diffusion du CO2 au-delà de la barrière stomatique et du tissu mésophyllien fût étudiée plus spécifiquement pour clarifier notre comprehension de la limitation microclimatique sur la production photosynthétique des framboisiers. La framboise d’été cultivée hors-sol a produit des tiges fructifères (primocanes) plus grandes et d’un diamètre plus élevé durant l’année de végétation ainsi que des rendements supérieurs lors de l’année de fructification. En 2013 et 2014, la croissance des plants, la masse sèche et les rendements de fruits vendables n’ont pas été significativement affectés par les trois conductivités électriques (CE) de la solution nutritive (témoin avec CE de 1,2 Ms/cm , CE inférieure avec 1,2 Ms/cm et 0,8 Ms/cm avant et après le début de la floraison et CE supérieure avec 1,6 Ms/cm et 1,2 Ms/cm avant et après le début de la floraison). En 2013 et 2014, le substrat constitué de biochar et celui constitué de fibres de coco ont occasionné une réduction de la masse sèche des racines des plants en comparaison avec le substrat constitué de tourbe et d’écorce et celui constitué d’un mélange de tourbe. Pour la framboise d’été, les plus grandes primocanes ont été obtenus avec les plants issus de boutures de racines lors de la première année de culture. Par contre, des rendements similaires ont été obtenus lors de l’année de fructification. Pour la framboise d’automne, même si des effets négatifs sur la hauteur des plants et la biomasse ont été observés avec les plants provenant de boutures de racines lors de la première année de culture, le rendement en fruits commercialisables a significativement augmenté. Suite à une défoliation artificielle de 42% des feuilles situées à l’intérieur de la canopée, la photosynthèse sous conditions lumineuses saturantes a augmenté. Par contre, les valeurs estimées de photosynthèse nette cumulative ont été similaires chez les plants témoins et les plants partiellement défoliés. Le rendement total n’a également pas été affecté par la défoliation artificielle. Des expériences complémentaires ont démontré qu’entre 20 et 35 ºC, la conductance du mésophylle au CO2 (gm) et la conductance stomatique (gs) ont diminué significativement. La réduction de gm et gs chez les plants de framboise soumis à une Tleaf (température de la feuille) élevée ou un VPDleaf élevé fut corrélée avec une augmentation significative de l’ABA foliaire.<br>En raison de la croissance importante de la demande des consommateurs pour la framboise, la production a connu un essor considérable au cours des dernières décennies. L’augmentation du rendement est une précoccupation des producteurs qui doivent répondre à cette demande. De plus, la croissance des plants de framboise peut être limitée et leur physiologie peut être affectée par des facteurs abiotiques (lumière, température, déficit de pression de vapeur). Dans ce contexte, cette thèse a étudié : 1) les méthodes de culture (la culture en plein champ versus la culture hors-sol, les régimes de fertigation, les substrats et les méthodes de propagation); 2) les effets de l’environnement (e.g. lumière) sur la photosynthèse, la conductance hydraulique du plant et des feuilles ainsi que le rendement en fruits. Notre hypothèse générale en ce sens étant que la surface foliaire élevée des cultures hors-sol de framboisiers pourrait limiter leur rendement en fruit dû à un ombragement excessif des zones fruitières et/ou à un manquement de la capacité hydraulique à rencontrer la demande évaporative. De plus, l’effet de la température foliaire et du déficit de pression de vapeur entre les feuilles et l’atmosphère (VPDleaf) sur la diffusion du CO2 au-delà de la barrière stomatique et du tissu mésophyllien fût étudiée plus spécifiquement pour clarifier notre comprehension de la limitation microclimatique sur la production photosynthétique des framboisiers. La framboise d’été cultivée hors-sol a produit des tiges fructifères (primocanes) plus grandes et d’un diamètre plus élevé durant l’année de végétation ainsi que des rendements supérieurs lors de l’année de fructification. En 2013 et 2014, la croissance des plants, la masse sèche et les rendements de fruits vendables n’ont pas été significativement affectés par les trois conductivités électriques (CE) de la solution nutritive (témoin avec CE de 1,2 Ms/cm , CE inférieure avec 1,2 Ms/cm et 0,8 Ms/cm avant et après le début de la floraison et CE supérieure avec 1,6 Ms/cm et 1,2 Ms/cm avant et après le début de la floraison). En 2013 et 2014, le substrat constitué de biochar et celui constitué de fibres de coco ont occasionné une réduction de la masse sèche des racines des plants en comparaison avec le substrat constitué de tourbe et d’écorce et celui constitué d’un mélange de tourbe. Pour la framboise d’été, les plus grandes primocanes ont été obtenus avec les plants issus de boutures de racines lors de la première année de culture. Par contre, des rendements similaires ont été obtenus lors de l’année de fructification. Pour la framboise d’automne, même si des effets négatifs sur la hauteur des plants et la biomasse ont été observés avec les plants provenant de boutures de racines lors de la première année de culture, le rendement en fruits commercialisables a significativement augmenté. Suite à une défoliation artificielle de 42% des feuilles situées à l’intérieur de la canopée, la photosynthèse sous conditions lumineuses saturantes a augmenté. Par contre, les valeurs estimées de photosynthèse nette cumulative ont été similaires chez les plants témoins et les plants partiellement défoliés. Le rendement total n’a également pas été affecté par la défoliation artificielle. Des expériences complémentaires ont démontré qu’entre 20 et 35 ºC, la conductance du mésophylle au CO2 (gm) et la conductance stomatique (gs) ont diminué significativement. La réduction de gm et gs chez les plants de framboise soumis à une Tleaf (température de la feuille) élevée ou un VPDleaf élevé fut corrélée avec une augmentation significative de l’ABA foliaire.<br>Due to the rapidly increasing demand by consumers, raspberry production has steadily increased during the last decades. It is becoming a major concern of the producers to efficiently cultivate raspberry and to improve their yield performance to meet this demand. Furthermore, raspberry plant growth and physiology are limited or affected by abiotic factors (i.e. light, temperature, vapour pressure deficit). In this context, this thesis examines: 1) the cultivation methods (soilless cultivation, fertigation regimes, substrates, and propagation methods) that could further improve raspberry production and 2) the effects of environmental factors (e.g. light penetration) on raspberry leaf photosynthetic parameters, leaf/plant hydraulic parameters and fruit production. Our general hypothesis was that the large leaf area index of soilless raspberry hedgerow cultures may limit fruit production due to excessive shading of fruiting points and/or insufficient hydraulic capacity to meet the foliar evaporative demand. Additionally, the effect of temperature and leaf-to-air vapour pressure deficit (VPDleaf) on CO2 diffusion across the stomatal and the leaf mesophyll were studied to improve our understanding of microclimatic limitations on raspberry photosynthetic production. Soilless cultivated summer-fruiting raspberries produced taller primocanes with larger cane diameter in the vegetative year and produced higher yields in the fruiting year. In both 2013 and 2014, plant growth, dry biomass and marketable yield were not significantly affected by the three fertigation schemes (Control: constant irrigation solution EC at 1.2 Ms/cm; Higher EC regime: irrigation solution EC value of 1.6 Ms/cm to 1.2 Ms/cm before and after the onset of flowering, respectively; Lower EC regime: irrigation solution EC value of 1.2 Ms/cm to 0.8 Ms/cm before and after the onset of flowering, respectively). Compared to peat/bark substrate, peat mixed with biochar and coco fibers substrates reduced root dry biomass in 2013 and 2014, respectively. In summer-fruiting raspberry, taller primocanes were obtained with root cutting plants in the first cultivation year, but similar yield was obtained in their fruiting year. In autumn-fruiting raspberry, although negative effects on plant height and biomass were observed with root cutting propagated plants during the first cultivation year, their marketable fruit yield was significantly improved. However, no difference in yield was found in their second year between root cutting and bare-root propagated plants. After 42% of the leaves inside the canopy were artificially removed, light-saturated photosynthesis was improved, but similar cumulative photosynthesis were estimated in both control and partially defoliated plants. Total yield was also not influenced by partial artificial defoliation. Further investigation showed that mesophyll conductance to CO2 (gm) and stomatal conductance (gs) decreased significantly from 20 to 35 ºC. The reduction of gm and gs under high Tleaf/VPDleaf correlated with a significant increase in foliar ABA.<br>Due to the rapidly increasing demand by consumers, raspberry production has steadily increased during the last decades. It is becoming a major concern of the producers to efficiently cultivate raspberry and to improve their yield performance to meet this demand. Furthermore, raspberry plant growth and physiology are limited or affected by abiotic factors (i.e. light, temperature, vapour pressure deficit). In this context, this thesis examines: 1) the cultivation methods (soilless cultivation, fertigation regimes, substrates, and propagation methods) that could further improve raspberry production and 2) the effects of environmental factors (e.g. light penetration) on raspberry leaf photosynthetic parameters, leaf/plant hydraulic parameters and fruit production. Our general hypothesis was that the large leaf area index of soilless raspberry hedgerow cultures may limit fruit production due to excessive shading of fruiting points and/or insufficient hydraulic capacity to meet the foliar evaporative demand. Additionally, the effect of temperature and leaf-to-air vapour pressure deficit (VPDleaf) on CO2 diffusion across the stomatal and the leaf mesophyll were studied to improve our understanding of microclimatic limitations on raspberry photosynthetic production. Soilless cultivated summer-fruiting raspberries produced taller primocanes with larger cane diameter in the vegetative year and produced higher yields in the fruiting year. In both 2013 and 2014, plant growth, dry biomass and marketable yield were not significantly affected by the three fertigation schemes (Control: constant irrigation solution EC at 1.2 Ms/cm; Higher EC regime: irrigation solution EC value of 1.6 Ms/cm to 1.2 Ms/cm before and after the onset of flowering, respectively; Lower EC regime: irrigation solution EC value of 1.2 Ms/cm to 0.8 Ms/cm before and after the onset of flowering, respectively). Compared to peat/bark substrate, peat mixed with biochar and coco fibers substrates reduced root dry biomass in 2013 and 2014, respectively. In summer-fruiting raspberry, taller primocanes were obtained with root cutting plants in the first cultivation year, but similar yield was obtained in their fruiting year. In autumn-fruiting raspberry, although negative effects on plant height and biomass were observed with root cutting propagated plants during the first cultivation year, their marketable fruit yield was significantly improved. However, no difference in yield was found in their second year between root cutting and bare-root propagated plants. After 42% of the leaves inside the canopy were artificially removed, light-saturated photosynthesis was improved, but similar cumulative photosynthesis were estimated in both control and partially defoliated plants. Total yield was also not influenced by partial artificial defoliation. Further investigation showed that mesophyll conductance to CO2 (gm) and stomatal conductance (gs) decreased significantly from 20 to 35 ºC. The reduction of gm and gs under high Tleaf/VPDleaf correlated with a significant increase in foliar ABA.

Post-planting silviculture in the exotic pine plantations of Southeast Queensland focuses on fertilisation and weed control at early plantation establishment. Early establishment silviculture in pine plantations aims to reduce the competition for light, nutrients and water in the short term, while maximising resource conversion for growth in the long term. However, silviculture can be applied in a systematic way without necessarily considering the limitations to maximum tree growth at each site. Accordingly, silvicultural treatments could be applied in a site specific manner to better reflect the limitations to tree growth at each site (e.g. nutrition and/or water), or for maximum effectiveness based on seasonal limitations (e.g. weed competition, water availability). This research aimed to investigate the effects of early establishment weed control and fertilisation practices on soil carbon (C) and nitrogen (N) cycling (as an indicator of soil fertility), tree nutrition (particularly N nutrition), growth and eco-physiological responses, in the F1 hybrid exotic pine plantations (Pinus elliottii Engelm var. elliottii x Pinus caribaea Morelet var. hondurensis (Sènècl.) W.H.G. Barett & Golfari.) in the subtropics of Southeast Queensland.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Environment<br>Science, Environment, Engineering and Technology<br>Full Text

Perennial grass vegetation dynamics of heavy grazing, moderate grazing and ungrazed treatments were analyzed during two extreme drought events: the drought of 1951 to 1956 and the drought events centered on the year 2000. Analysis of each drought event from weather records and Palmer Drought Severity Index values showed that the intensity, duration and pattern of each drought event were structurally unique. Grazing intensity was the primary driver of perennial grass species composition and community structure both during and between each drought event. Total basal area for each drought event was driven primarily by variation in precipitation pattern. Basal area per plant dynamics were significantly influenced by grazing intensity while plant density was driven by both precipitation and grazing intensity. Topo-edaphic variation significantly influenced the persistence and distribution of perennial grass species during an extreme drought event centered on the year 2000. The presence of large or abundant surface rock features facilitated the survival of perennial grasses during this drought event by creating a positive soil microenvironment. Sites with large surface rock features acted as drought refugia for perennial grass populations. Sites with abundant surface rock features had 10 times greater perennial grass basal area and 5 times greater plant density than sites with few surface rock features. Grazing intensity was the primary driver of species composition and community structure within both refugia and non-refugia sites. Grazing intensity had no effect on perennial grass basal area. However, grazed treatments had two times greater perennial grass density than non-grazed treatments. Species response to grazing intensity and surface rock cover was individualistic. Grazing response groups (intolerant, intermediate, and tolerant) separated along a gradient of surface rock cover and grazing intensity. Abundant surface rock features act as refugia for perennial grasses by facilitating their persistence during extreme drought events on the Edwards Plateau.

The Greater Cape Floristic Region (GCFR) is divided into two subregions, the Core Cape Subregion (CCR) and Extra Cape Subregion (ECR), which are mainly characterized by Fynbos and Succulent Karoo biomes, and are recognized among global biodiversity hotspots. The soils in the ECR are mostly shale derived and richer in nutrients compared to the CCR which is characterized by nutrient-poor sandstone soils mainly from the Cape System. The Fabaceae (Leguminosae) is the second largest family in the CCR with a total of about 764 species (belonging to 43 genera, of which 83% of the species are endemic to the CCR), and sixth largest in the ECR with about 140 species currently recognised with 39.3% of these species endemic to the ECR. Wiborgia Thunb. is a legume genus made up of 9 perennial shrub species of height 0.5-3.0 metres, with distinct ascending to erect habit, which share morphological similarities with some Lebeckia, especially sect. Viborgoides currently referred to as Wiborgiella. The aim of this dissertation was to understand the evolution and biogeography of the genus Wiborgia in the GCFR. This involved (i) inferring phylogenetic relationships within the genus using multiple molecular markers and testing the monophyly and the support of Dahlgren's (1975) morphological subgeneric classification; (ii) determining nutritional characteristics of soils occupied by different Wiborgia species and compare them with sites where Wiborgia species have not been recorded to occur and testing whether Wiborgia species occupy habitats with similar nutrient concentrations; (iii) evaluating the potential of Wiborgia species to grow and nodulate in soils from within and outside distribution range and characterizing of rhizobia nodulating Wiborgia species in field and glasshouse conditions. Phylogenetic relationships in Wiborgia were inferred using multiple molecular markers (ITS, rpl32-trnL, rps16, trnS-trnG, and trnT-trnL) and the data were analysed using model based approaches (Maximum Likelihood, Bayesian inference). Wiborgia was well supported as monophyletic and sister to both Wiborgiella and Aspalathus, with Wiborgiella humilis well supported as being part of the Wiborgiella clade. Within the Wiborgia clade, two strongly supported subclades were observed. In subclade 1, W. tetraptera was strongly supported as sister to W. fusca, whilst W. monoptera was strongly supported as sister to W. incurvata. In subclade 2, a novel well-supported sister relationship between W. mucronata and W. tenuifolia was observed. Wiborgia obcordata, the only species in Dahlgren's subgenus Wiborgia, was found to be embedded within subgenus Pterocarpia and thus the subgenera classification of Dahlgren was not supported. It was also identified that sister species pairs (W. incurvata and W. monoptera; W. fusca and W. tetraptera; W. tenuifolia and W. mucronata) all showed the tendency to co-occur or have overlapping distribution ranges, and showed subtle differences in floral morphology and habitats.

Master of Science<br>Statistics<br>Nora M. Bello<br>Big bluestem (Andropogon gerardii) is a wide-ranging dominant prairie grass of ecological and agricultural importance to the US Midwest while edaphic subspecies sand bluestem (A. gerardii ssp. Hallii) grows exclusively on sand dunes. Sand bluestem exhibits phenotypic divergence related to epicuticular properties and enhanced drought tolerance relative to big bluestem. Understanding the mechanisms underlying differential drought tolerance is relevant in the face of climate change. For bluestem subspecies, presence or absence of these phenotypes may be associated with RNA transcripts characterized by low number of read counts. So called low-count transcripts pose particular inferential challenges and are thus usually filtered out at early steps of data management protocols and ignored for analyses. In this study, we use a plasmode-based approach to assess the relative performance of alternative inferential strategies on RNA-seq transcripts, with special emphasis on low-count transcripts as motivated by differential bluestem phenotypes. Our dataset consists of RNA-seq read counts for 25,582 transcripts (60% of which are classified as low-count) collected from leaf tissue of 4 individual plants of big bluestem and 4 of sand bluestem. We also compare alternative ad-hoc data filtering techniques commonly used in RNA-seq pipelines and assess the performance of recently developed statistical methods for differential expression (DE) analysis, namely DESeq2 and edgeR robust. These methods attempt to overcome the inherently noisy behavior of low-count transcripts by either shrinkage or differential weighting of observations, respectively. Our results indicate that proper specification of DE methods can remove the need for ad- hoc data filtering at arbitrary expression threshold, thus allowing for inference on low-count transcripts. Practical recommendations for inference are provided when low-count RNA-seq transcripts are of interest, as is the case in the comparison of subspecies of bluestem grasses. Insights from this study may also be relevant to other applications also focused on transcripts of low expression levels.

Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(人間・環境学)<br>甲第21177号<br>人博第849号<br>新制||人||203(附属図書館)<br>29||人博||849(吉田南総合図書館)<br>京都大学大学院人間・環境学研究科相関環境学専攻<br>(主査)教授 瀬戸口 浩彰, 教授 加藤 眞, 教授 市岡 孝朗<br>学位規則第4条第1項該当

Abstract Air and soil temperatures, snow cover, serious snow load damage to coniferous trees, wind, topography and edaphic factors on the fells situated between 67°N and 68°N in Finnish Lapland are described and their influence on the location of the actual timberline and treeline is discussed. In addition the relation between annual climate conditions and pollen deposition in the timberline ecotone is analysed and the results of seedling density monitoring in the same environment are presented. The potential for the actual timberline and treeline to advance to a higher elevation is also discussed. The field studies were carried out on the fells of Aakenustunturi, Yllästunturi and Pyhätunturi. The average altitude of the actual timberline varies from 370 metres to 402 metres a.s.l. The actual timberline is hardly ever composed of a single tree species but featured alternating occurrences of Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and mountain birch (Betula pubescens ssp. czerpanovii). The mean tetratherms on the southern and northern slopes (+10.3°C and +10.1°C, respectively), the mean maximum tetratherm on the southern slope (+15.1°C) and the corresponding measures for the treeline (460 m a.s.l), the minimum tetratherm (+6.3°C), mean July temperature (+12.6°C), biotemperature (+3.3°C) and minimum effective temperature sum (455 d.d.), coincide closest with the results of earlier studies. The maximum altitudes of the actual timberline are dictated by many climatic factors on southern and western slopes with a gentle inclination, and the forest cover gradually becomes thinner, in which case the actual timberline does not form any easily distinguishable line. The lowest altitudes of the actual timberline are the results of an extremely high proportion of block fields, slope steepness and snow patches on the northern and eastern slopes. On the precipitous and rocky slopes trees have difficulties in taking root and in obtaining nutrients and water, while as a consequence of snow patches the growing season may be too short for tree growth at all, and if trees exist there they are suffering from low soil temperature and parasitic snow fungi. Serious snow load damage to trees evidently hampers any advance in the actual timberline, as do avalanches and mires. The location of the treeline is the result of a combination of a great number of unfavourable conditions for tree regeneration, seedling establishment and tree growth, such as inadequate snow protection, extreme soil temperatures, almost total destruction of trees by the snow load, wind pressure, an often inadequate effective temperature sum and length of the growing season, night frost in early summer, and poor, dry soil suffering from excessive evaporation. Actual timberline responses to predicted climate warming will differ greatly from site to site in relation to the local topography, edaphic features and associated ecological limitations. Any advance in the treeline to a higher elevation is likely to be slower and at least less certain than that in the actual timberline. In addition, advances in the actual timberline and treeline may even be prevented by phenomena occurring along with climate change. A potential key factor in this is serious snow load damage to the trees.

Este trabalho objetivou conhecer e comparar a diversidade de formigas em três fragmentos florestais (Cananéia, Ibicatu e Pariquera-Açu) do Estado de São Paulo. As coletas foram realizadas em serapilheira e na camada mineral (0-5 cm de profundidade), na base de Euterpe edulis. As formigas foram coletadas, utilizando-se sonda cilíndrica de alumínio de 10 cm de diâmetro por 5 cm de altura, a qual era introduzida na serapilheira e no solo; depois triadas, montadas e identificadas. Os dados foram submetidos a análise de variância (ANOVA). Com o programa ANAFAU calcularam-se os índices faunísticos, a diversidade pelo método de Shannon- Wiener (H), os índices de eqüitabilidade (E) e similaridade. A riqueza estimada de espécies, o número de espécies singletons e doubletons e a curva de acumulação de espécies foram calculadas pelo programa EstimateS. As formigas também foram separadas em guildas, com base em aspectos biológicos. Pela análise da suficiência amostral em cada fragmento florestal, observou-se que Cananéia e Pariquera-Açu foram mais homogêneos do que Ibicatu. O número de amostras não foi suficiente para caracterizar os ambientes, pois a curva do coletor não se estabilizou. As formigas foram agrupadas em 9 guildas, sendo que 3 foram consideradas novas. Esses resultados fornecem subsídios para o conhecimento taxonômico e ecológico das espécies de formigas que habitam alguns trechos da Mata Atlântica paulista.<br>This research deals with the diversity of ants in three forest fragments (Cananéia, Ibicatu, and Pariquera-Açu) of the State of São Paulo, Brazil. The insects were collect by using an aluminium cylindrical device introduced into the litter and the soil layer (0 to 5 cm deep) around the base of Euterpe edulis trees. The ants were then taken to the laboratory, pin-mounted and identified. The data were submitted to the analysis of variance (ANOVA). The faunistic, equitability (E) and similarity indexes, and the diversity by the Shannon-Wiener (H) method, were calculated through the ANAFAU program. The estimated species richness, the number of singleton and doubleton species and the accumulation curve of species were calculated by the EstimateS program. The ants were separated into guilds, based in biological aspects. The analysis of sufficiency sampling of each forest fragment indicated that Cananéia and Pariquera-Açu were more homogeneous than Ibicatu. The number of samplings were not sufficient to caracterize the environments for the collector curve did not stabilized. The ants were grouped into nine guilds, being three of them considered new ones. Broadly speaking, the results provide data for the taxonomic and ecological knowledge of ant species occurring in some parts of the São Paulo State Atlantic Forest.

Made available in DSpace on 2015-03-26T13:32:11Z (GMT). No. of bitstreams: 1 texto completo.pdf: 852842 bytes, checksum: 70e1222560798c97f05cf66d73772591 (MD5) Previous issue date: 2011-02-25<br>Logistic regression is the analysis usual statistical method used to verify the relationship between a dichotomous variable response and the interest explanatory variables. This work aimed to carry out a study about the factors influencing the invertebrates abundance on the soil under different management forms, using the logistic regression. This objective is that these invertebrates are considered excellent indicators of the use type and soil quality, working in several fundamental processes for maintaining the soil fertility and quality in agroecosystems and natural ecosystems, according to Brown et al. (1998), Hendrix et al. (2006), and Souza (2010). For covariates selection, the Collett (1994) proposal was used and the involved parameters estimators in each model, their interpretations, statistical properties, and some criteria for judging the suitability of the selected models were presented. The methodology presented by this work was applied to two real datasets (dry and rainy season). In the final adjusted model for the analyzed dataset in the dry season, it was verified that the covariates System Type, Calcium in litter, Soil organic matter, Potassium in litter, and the interaction between Calcium and Potassium in litter were important to explain the presence of more than nine individuals on the soil. In the final adjusted model for the analyzed dataset in the rainy season, the significant covariates to explain the presence of one hundred and one individuals on average on the soil were Magnesium in litter, Total organic carbon in the litter, Litter organic matter, and Ambient temperature. For two mentioned models, there were a good discriminatory performance and excellent areas under the ROC (Receiver Operating Characteristic) curve, thus confirming the validity of using logistic regression techniques for the models construction to describe the analyzed data.<br>A regressão logística é o método estatístico usual de análise utilizado com a finalidade de verificar a relação entre uma variável resposta dicotômica e variáveis explicativas de interesse. Este trabalho teve como objetivo realizar um estudo sobre os fatores que influenciam a abundância de invertebrados no solo sob diferentes formas de manejo utilizando a Regressão Logística. Tal objetivo reside no fato destes invertebrados serem considerados excelentes indicadores do tipo de uso e qualidade do solo, atuando em vários processos fundamentais para a manutenção da fertilidade e qualidade dos solos de agroecossistemas e ecossistemas naturais de acordo com Brown et al. (1998) e Hendrix et al. (2006), citado Souza (2010). Para seleção de covariáveis foi utilizada a proposta de Collett (1994) e foram apresentados estimadores dos parâmetros envolvidos em cada modelo e suas interpretações, propriedades estatísticas e critérios para se julgar a adequabilidade dos modelos selecionados. A metodologia apresentada neste trabalho foi aplicada a dois conjuntos de dados reais (período seco e chuvoso). No modelo final ajustado para o conjunto de dados analisado no período seco verificou-se que as covariáveis Tipo de Sistema, Cálcio em serapilheira, Matéria orgânica do solo, Potássio em serapilheira e a interação entre Cálcio e Potássio em serapilheira foram importantes para explicar a presença de mais de 9 indivíduos, em média, no solo. Já no modelo final ajustado para o conjunto de dados analisado no período chuvoso, as covariáveis significativas para explicar a presença de 101 indivíduos, em média, no solo foram Magnésio em serapilheira, Carbono orgânico total na serapilheira, Matéria orgânica da serapilheira e Temperatura ambiente. Para os dois modelos citados houve bom desempenho discriminatório e excelentes áreas sob a curva ROC, confirmando assim a validade da utilização de técnicas de regressão logística na construção dos modelos para descrever os dados analisados.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-30T12:11:20Z No. of bitstreams: 1 JOSÉ DA SILVA SOUSA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 1561653 bytes, checksum: aa1844de8c3babe6fa251dc328c9832c (MD5)<br>Made available in DSpace on 2018-05-30T12:11:20Z (GMT). No. of bitstreams: 1 JOSÉ DA SILVA SOUSA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 1561653 bytes, checksum: aa1844de8c3babe6fa251dc328c9832c (MD5) Previous issue date: 2014-11-11<br>O coentro (Coriandrum sativum L.) é uma olerícola herbácea anual com altura média de 10 a 20 cm planta-1, dependendo das condições edáficas que esteja sendo cultivado, da cultivar e adubação. O seu cultivo é principalmente voltado para atender à demanda para o consumo fresco de hastes e para as indústrias de condimentos. Nesse sentido a pesquisa objetivou avaliar a jitirana (Merremia aegyptia), flor-de-seda (Calotropis procera) e mata-pasto (Senna uniflora) como fonte de adubo verde no desempenho agroeconômico do coentro. O experimento foi conduzido na Fazenda Experimental Rafael Fernandes, localizada no distrito de Alagoinha, zona rural de Mossoró-RN, no período de julho a setembro de 2013. O delineamento experimental utilizado foi em blocos completos casualizados, com os tratamentos arranjados em esquema fatorial 4 x 3, com 3 repetições. Os tratamentos consistiram da combinação de quatro quantidades de espécies espontâneas (0,4; 0,8; 1,2 e 1,6 kg/m2) e o segundo fator, correspondendo a três tipos de espécies espontâneas (jitirana, flor-de-seda e mata-pasto). Cada parcela constou de doze fileiras de plantas espaçadas de 0,1 m x 0,05 m, com 05 plantas cova-1. Dez dias após a emergência realizou-se o desbaste, trinta e três dias após o plantio foi realizada a colheita. As características avaliadas foram as seguintes: altura de planta, número de hastes por planta, massa fresca de coentro, massa seca de coentro e número de molhos de coentro, os parâmetros econômicos foram: Renda bruta, renda líquida, taxa de retorno por real investido e índice de lucratividade. Para altura de planta em relação aos tipos de adubos verdes, observou-se diferença da jitirana em relação a florde- seda e mata-pasto, com valores médios de 18,9; 16,8 e 16,0 cm planta-1. Para a massa fresca, observou-se que a jitirana foi superior à flor-de-seda e mata-pasto, com produtividade máxima de 0,9; 0,7 e 0,8 kg m-2 de canteiro, equivalente a 18, 14 e 16 molhos m-2 de canteiro, na quantidade de 16,0 t ha-1. A aplicação de espécies espontâneas da caatinga, proporcionou rentabilidade líquida de R$ 6.070,00, taxa de retorno da ordem de R$ 2,80 e índice de lucratividade de 64,2% para jitirana. Rentabilidade líquida de R$ 2.920,00, taxa de retorno de 1,86 e índice de lucratividade de 46,3% para a flor-de-seda e rentabilidade líquida de R$ 4.270,00, taxa de retorno de 2,26 e índice de lucratividade de 55,8%. Nesse sentido, o cultivo de coentro adubado com espécies espontâneas da caatinga constitui-se em alternativa como adubo verde.<br>Coriander (Coriandrum sativum L.) is an annual herbaceous vegetable crop with average height 10-20 cm plant-1, depending on the soil conditions that are being grown, cultivar and fertilization. Its cultivation is mainly geared to meet the demand for fresh consumption stems and condiments industries. In this sense the research aimed to evaluate the jitirana (Merremia aegyptia), silk-flower (Calotropis procera) and kills pasture (Senna uniflora) as a source of green manure on agroeconomic performance of cilantro. The experiment was conducted at the Experimental Farm Rafael Fernandes, located in the district of Alagoinha, rural area of Mossoró-RN, in the period from July- September 2014. The experimental design was complete randomized block with treatments arranged in a factorial 4 x 3, with 3 repetitions. Treatments included a combination of four amounts of wild species (0,4; 0,8; 1,2 e 1,6 kg/m2) and the second factor, corresponding to three types of spontaneous species (jitirana, silk-flower and bush-pasture). Each plot consisted of twelve rows of plants spaced 0,1 mx 0,05 m, with 05 plants pit-1. Ten days after germination thinning took place thirty-three days after the planting to harvest was performed. The characteristics evaluated were: plant height, number of stems per plant, fresh coriander mass, dry mass and number of bunches cilantro coriander, economic parameters were: gross income, net income, rate of return per dollar invested and profitability index. Plant height in relation to the types of green manures, a difference was observed in relation to the jitirana-flowered silk-flower and bush-pasture, with average values of 18.9; 16.8 and 16.0 cm plant-1. For fresh pasta, it was observed that the jitirana was superior to silk-flower and bush-pasture and woods with maximum productivity of 0,9; 0,7 to 0,8 kg m-2 construction, equivalent to 18, 14 and 16 m2 sauces construction, the quantity of 16.0 t ha-1. The application of spontaneous caatinga species yielded net profit of R $ 6.070,00, return rate of R$ 2,80 and the profit margin of 64,2% for jitirana. Net profit of R $ 2.920,00, rate of return of 1.86 and profitability index of 46,3% for the silk-flower and net profit of R$ 4.270,00, rate of return of 2,26 and profitability index of 55,8%. Accordingly, the cultivation of coriander fertilized with wild species of the caatinga constitutes alternatively as green manure.

Orientador: Anselmo Nogueira<br>Resumo: Questões: Como é o padrão da diversidade e composição de espécies lenhosas ao longo do cerrado sensu stricto? Quais fatores abióticos estruturam essa diversidade e composição de espécies? Localização: Região do Cerrado no central do Brasil. Metodologia: Distribuímos 34 parcelas permanentes em sete unidades de conservação que possuíssem porções de vegetação cerrado sensu stricto. Aplicando modelos lineares mistos para investigar como é o padrão de distribuição da diversidade – riqueza e alfa de Fisher – e composição de espécies estariam relacionados com os fatores edáficos, climáticos e de pontos de incêndios, no qual o sítio foi tratado como variável randômica nos modelos. Para as análises de composição de espécies utilizamos dados de ocorrência e aplicamos um índice de dissimilaridade estendido para obter os eixos de ordenação em análises de coordenadas principais (PCoA). Análises de matrizes de Mantel simples e parcial também foram aplicados para explorar o papel do espaço na estruturação da comunidade e dos fatores abióticos. Resultados: Embora em nossa escala de amostragem não tenha sido possível identificar fatores preditivos da riqueza de espécies lenhosas, a composição de espécies esteve relacionada com o gradiente de precipitação e frequência dos pontos de incêndio ao longo do Cerrado. Os fatores edáficos não parecem ser determinantes, e sua importância relativa deve ser menor dentro dessa fitofisionomia do Cerrado ou na escala sob estudo. Embora o fogo, como fonte de... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Questions: How is the diversity pattern and composition of woody species through cerrado sensu stricto? Which abiotic factors structure this species diversity and composition? Location: Brazilian’s central Cerrado region Methodology: We distributed 34 permanent plots into seven conservation units that had portions of cerrado sensu stricto vegetation. Applying the linear mixed model to investigate how the diversity distribution pattern and species composition would be related with edaphic factors, climatic, and fire frequency in which the site was treated as random variable in the models. For the analysis of species composition, we used a dataset of occurrence, and we applied an index of extended dissimilarity to obtain the ordered axis in Principal Coordination of Analysis (PCoA). Analyses of simple and partial Mantel were also applied to explore the role of distance in the community structural and abiotic factors. Results: Although in our scale of samples were not possible to identify predictive factors of woody species richness, the composition of species were related with the precipitation gradient and frequency of fire frequency through Cerrado. The edaphic factors do not seem to be determined, and its relative importance should be lower in the fitofisionomy of Cerrado or the studied scale. Though the fire, as a source of disturbance recurrent on Cerrado, has given more significant importance in literature explaining a great part of differences in the vegetation biomass b... (Complete abstract click electronic access below)<br>Mestre