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Dissertations / Theses on the topic 'Plant species richness'

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1

Vonlanthen, Corinne Maria. "Alpine plant communities : ecology and species richness /." [S.l.] : [s.n.], 2005. http://www.zb.unibe.ch/download/eldiss/05vonlanthen_c.pdf.

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Dupré, Cecilia. "Regional and local variation in plant species richness." Doctoral thesis, Uppsala universitet, Institutionen för evolutionsbiologi, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-691.

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In this thesis, I examine the variation in plant species richness along gradients of productivity and disturbance in grasslands and forest habitats in southern Sweden, and I compare the documented patterns with theoretical predictions. Moreover, I evaluate the relative importance of habitat quality and habitat configuration for the occurrence of field layer species in deciduous forests. Finally, I present a new method for the determination of the regional species pool. To examine regional and local variation in plant species richness, I gathered data on species composition in plots of differen
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Dupré, Cecilia. "Regional and local variation in plant species richness /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5064-4/.

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Harral, Josephine Erica. "Experiments on resource availability and plant species richness." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415053.

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5

Downer, Monica Ruth. "Plant Species Richness and Species Area Relationships in a Florida Sandhill." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4030.

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Pine sandhill are integral pyrogenic communities in the southeastern United States. Though once widespread, habitat destruction, fire suppression and fragmentation have reduced the population to nearly 3%. It is important to learn as much as possible about these unique areas in order to implement best management practices to conserve and restore the existing populations of these communities. Fire is central to the maintenance of pine sandhill communities and two conceptual hypothesis regarding burn frequency have come to light in maintaining the unique species composition and richness of these
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Williams, Brandon M. "The influence of soil heterogeneity on plant species richness." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/10650.

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Environmental heterogeneity is often cited as one of the driving mechanisms behind community species composition and diversity. However, its contribution to species composition in plant communities remains unclear because few experiments demonstrate a causal link between environmental heterogeneity and plant diversity. This is particularly true for soil manipulations despite that fact that soil is expected to provide the key resources necessary for plant growth. Here, I utilize a unique manipulation of the soil profile to create communities with spatially heterogeneous and homogeneous soil arr
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Steinmann, Katharina. "Testing basic assumptions of species richness hypotheses using plant species distribution data /." Zürich, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000254735.

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8

Pollock, Michael Moritz. "Patterns of plant species richness in emergent and forestry wetlands of southeast Alaska /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/5518.

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Hampton, Mark Edward. "The effects of disturbance and herbivory on plant community structure, plant recruitment and species richness." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417237.

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10

Boag, Angela Elaine. "Spatial models of plant species richness for British Columbia's Garry oak meadow ecosystem." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46920.

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Garry oak meadow ecosystems in British Columbia are fragmented, increasingly degraded, and have been prioritized for conservation. While distribution maps of remnant meadow patches have been developed, the ecological integrity of plant communities in many of these remnants remains unknown. Modeling and mapping ecological integrity could inform conservation prioritization exercises in the region. The primary goal of this thesis was to develop distribution models of native and exotic plant species richness in Garry oak meadow remnants. Secondly, multiple independent datasets were used to
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Duncan, Allison B. "Relationship between remnant size and plant species richness in the Tucson urban matrix." Thesis, The University of Arizona, 2002. http://hdl.handle.net/10150/278795.

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The Sonoran Desert surrounding Tucson, Arizona is the dominant matrix in a region undergoing a transition from desert matrix to urban matrix with little emphasis placed on preserving this native ecosystem intact. Instead, patches of desert, remnants, are cut off the desert matrix and surrounded by a variety of land uses including residential, transit, and commercial. 31 sites within the City of Tucson were surveyed and the site's plant species richness, woody cover, herbaceous cover, and disturbance percentage measured. The plants found on-site were classified into native or exotic, annual or
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12

Steffan, Shawn Alan. "Biodiversity and fear ecology the cascading effects of species richness and nontrophic interactions /." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/s_steffan_041709.pdf.

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Wilson, Frederick. "Factors affecting the species richness of old permanent semi-natural grasslands in North-East Scotland." Thesis, University of Aberdeen, 2003. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU173020.

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The successful management for conservation and restoration of semi-natural ecosystems may be achieved only after the factors which regulate plant biodiversity and species composition have been identified. This study investigates the floristic composition and site characteristics of old permanent semi-natural grasslands in North-east Scotland and tests using pot and field experiments the role of soil fertility in determining vascular plant species richness, relative abundance and dynamics of communities. Results from field surveys show that, of the site characteristics quantified, vascular plan
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Pinto, Leonardo Henrique Teixeira. "Restoration of plant diversity and ecosystem functioning: effects of species richness, phylogenetic distance, functional diversity and invasive plants." PROGRAMA DE P?S-GRADUA??O EM ECOLOGIA, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/23964.

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Van, Tonder Carlo. "Factors influencing species richness, cover and composition of vegetation on Namaqualand quartz fields." Thesis, Nelson Mandela Metropolitan University, 2006. http://hdl.handle.net/10948/630.

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Quartz fields contribute significantly to plant diversity in the Succulent Karoo biome. They are distinctly different from surrounding habitats and have high levels of plant endemism. Biological soil crusts are features of quartz field soils and fulfill a vital function in that they stabilize soils. It is important for managers of nature reserves and agricultural rangelands to know what factors influence quartz field soils and vegetation. Both stakeholders could benefit from new information that would allow for informed decision-making regarding land-use on quartz fields. The present study too
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TORDONI, ENRICO. "ANALYSIS OF DIVERSITY PATTERNS OF NATIVE AND ALIEN SPECIES IN COASTAL PLANT COMMUNITIES: FROM LOCAL TO GLOBAL SCALE." Doctoral thesis, Università degli Studi di Trieste, 2018. http://hdl.handle.net/11368/2924761.

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Coastal ecosystems are deemed one of the most productive ecosystem in the world hosting habitat and species of great ecological and conservation values. As a direct consequence of urbanization and globalization, these ecosystems are undergoing several threats among which biological invasions represent one of major concern. A clear and comprehensive understanding of the invasion process in these habitats is still lacking; in this thesis, I explored the diversity patterns of native and alien species along with the main ecological determinants shaping coastal plant communities from local to globa
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Hoare, David Barry. "Patterns and determinants of species richness in mesic temparate grasslands of South Africa." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1275.

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The aim of this study is to gain a predictive understanding of the patterns and determinants of plant biodiversity in temperate, mesic grasslands of South Africa with a primary focus on the geographical area of the Eastern Cape. From a review of the literature on hypotheses explaining diversity (Chapter 2) it was possible to formulate a number of hypotheses that could be tested to explain species richness patterns in Eastern Cape grasslands. This thesis is organised so that each main chapter deals with a specific body of theory concerning the explanation of diversity patterns. A detailed descr
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Oliveira, Aliane Maria de [UNESP]. "Caracterização de uma comunidade de árvores e sua infestação por lianas em uma floresta decídua." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/95081.

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Made available in DSpace on 2014-06-11T19:27:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-11Bitstream added on 2014-06-13T20:16:47Z : No. of bitstreams: 1 oliveira_am_me_botib.pdf: 3138768 bytes, checksum: 29295f39631d00207dcd4a354dfb5eeb (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Caracterização, diversidade, estrutura e estágio sucessional da comunidade de árvores de uma Floresta Estacional Decidual no Sudeste do Brasil. A composição florística, a estrutura, a diversidade e o estágio sucessional de um fragmento de floresta foram analisad
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Petersen, Hana. "Patterns of plant species richness and diversity across two habitat types in the Upper Karoo, South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29209.

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The Nama-Karoo biome is relatively understudied in terms of its baseline biodiversity. Apart from its rich agricultural land-use history, the region is also under pressure from the development of the Square Kilometre Array, an increased demand for cleaner energy from shale gas fracking and/or other renewable energy installations, and the overarching impacts of global climate change. A reliable baseline inventory of biodiversity for the region is essential if these impacts are to be monitored and managed effectively. The main aim of this study was to relate fine-scale patterns of plant diversit
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Johnson, Catherine E. "Role of Plant Species Richness in Green Roof Plots on the Quantity and Quality of Stormwater Runoff." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397734513.

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21

Lejon, Anna G. C. "Ecosystem response to dam removal." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55586.

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This thesis aims to improve our understanding of how riverine ecosystems respond to dam removal. Riverine and particularly riparian ecosystems are among the most variable and important features of all landscapes. They connect landscape elements both longitudinally and laterally, and are governed by processes such as flooding, erosion and deposition that create dynamic, diverse and heterogeneous habitats. In fact, riparian zones are among the world’s most species-rich habitats. Worldwide there are millions of dams that fragment stream and river systems, regulate flows and degrade ecosystems. Da
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22

Haig, April Raissa. "The effect of habitat fragmentation on lichen and plant species richness of Niagara Escarpment cliffs in Ontario, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24475.pdf.

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23

Medinski, Tanya. "Soil chemical and physical properties and their influence on the plant species richness of arid South-West Africa." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/2157.

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Thesis (MScConsEcol (Conservation Ecology and Entomology)--University of Stellenbosch, 2007.<br>Understanding the drivers and mechanisms of changes in plant richness is a basis for making scientifically sound ecological predictions and land use decisions. Of the numerous factors affecting plant richness, soil has a particularly large influence on the composition and structure of terrestrial flora. Infiltrability is one of the most important factors determining soil moisture, and therefore is of particular interest in semi-arid ecosystems, where water is one of the most limiting resources. Othe
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24

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

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25

Hancock, Christopher Nigel. "Factors affecting the physiognomy and species richness of plant communities of valleys of the Darling Plateau, Western Australia." Thesis, Hancock, Christopher Nigel (2002) Factors affecting the physiognomy and species richness of plant communities of valleys of the Darling Plateau, Western Australia. PhD thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/51804/.

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Native vegetation along and near watercourses on the Darling Plateau, east of Perth, Western Australia was studied in order to identify the key environmental parameters affecting structure and species richness. Measurements were taken of vegetation height, cover and species richness, together with groundwater levels and a range of edaphic parameters. Floristic data were used to sort releves into community types. One upland, three riparian margin and four riparian plant community types were identified. The greatest degree of floristic and environmental change across the valley floor occurred
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26

Zinko, Ursula. "Plants go with the flow : predicting spatial distribution of plant species in the boreal forest." Doctoral thesis, Umeå : Ekologi och geovetenskap, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-315.

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27

Oliveira, Aliane Maria de. "Caracterização de uma comunidade de árvores e sua infestação por lianas em uma floresta decídua /." Botucatu : [s.n.], 2011. http://hdl.handle.net/11449/95081.

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Orientador: Andréia Alves Rezende<br>Banca: Maria Tereza Grombone Guaratini<br>Banca: Roque Cielo Filho<br>Resumo: Caracterização, diversidade, estrutura e estágio sucessional da comunidade de árvores de uma Floresta Estacional Decidual no Sudeste do Brasil. A composição florística, a estrutura, a diversidade e o estágio sucessional de um fragmento de floresta foram analisados nesse estudo. O trabalho foi desenvolvido no município de Votuporanga, onde o clima é considerado Aw. Foi utilizado o método de parcelas (1 ha), amostrando todos os indivíduos arbóreos com DAS 5 cm. Foram calculados os v
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Levy, Foster, and Elaine S. Walker. "Vascular Flora of the Rocky Fork Tract, Tennessee, USA, and Its Use in Conservation and Management." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/709.

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A flora of the 3800 ha Rocky Fork Tract in northeast Tennessee produced 749 species of which 19 were on the Tennessee Rare Plant List and 34 were on the Cherokee National Forest Species Viability List with 87 county records from Greene County and 217 from Unicoi County. Rare species were particularly numerous in the Cyperaceae and Orchidaceae. The tract serves as a refuge for several regionally uncommon species by supporting either large populations or metapopulations of these species. Exotic species comprised 15% of the flora and were most common in the Fabaceae and Poaceae. The most unique h
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Gerstner, Katharina Verfasser], Ralf [Akademischer Betreuer] [Seppelt, and Jürgen [Akademischer Betreuer] Dengler. "The global distribution of plant species richness in a human-dominated world : [kumulative Dissertation] / Katharina Gerstner ; Ralf Seppelt, Jürgen Dengler." Halle, 2016. http://d-nb.info/1116951657/34.

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Day, Nicola J. "Two decades of vegetation change across tussock grasslands in New Zealand's South Island." Master's thesis, Lincoln University. Bio-Protection and Ecology Division, 2008. http://theses.lincoln.ac.nz/public/adt-NZLIU20080304.145252/.

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New Zealand's South Island tussock grasslands have been highly modified by human activities, including burning, grazing and introductions of exotic plants for pastoralism. Studies suggest that tussock grasslands are degraded, in that native species have declined, and exotic species have increased in both diversity and abundance. These trends are primarily thought to be related to the impacts of grazing and subsequent grazing removal. Few studies have assessed long-term changes that have occurred in tussock grasslands, and those that have are generally limited to one particular location. This t
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Esther, Alexandra. "Investigating mechanisms maintaining plant species diversity in fire prone Mediterranean-type vegetation using spatially-explicit simulation models." Phd thesis, Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4463/.

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Fire prone Mediterranean-type vegetation systems like those in the Mediterranean Basin and South-Western Australia are global hot spots for plant species diversity. To ensure management programs act to maintain these highly diverse plant communities, it is necessary to get a profound understanding of the crucial mechanisms of coexistence. In the current literature several mechanisms are discussed. The objective of my thesis is to systematically explore the importance of potential mechanisms for maintaining multi-species, fire prone vegetation by modelling. The model I developed is spatially-ex
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Flint, Andrew R. "The biodiversity of the Wealden ghyll woodlands : species richness, abundance and distribution patterns in a rare and fragmented habitat." Thesis, University of Brighton, 2014. https://research.brighton.ac.uk/en/studentTheses/77f93fe9-19d0-4c2f-863d-b12e5edec87d.

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The Wealden ghyll woodlands are associated with unique plant assemblages that include nationally rare bryophyte species with oceanic affiliations. The identification and monitoring of this type of 'priority' habitat, recognised as important in terms of regional and national biodiversity, is a central facet of the UK Biodiversity Action Plan (UKBAP). Despite the acknowledged importance of ghyll woodlands for non-vascular plant species, previous studies attempting to examine and characterise the ghyll woodlands have neglected to include these bryophyte communities. This research identifies and c
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Larouche, Martine. "Effects of past land use and landscape context on plant species composition and richness in woodlots of an agricultural landscape in Québec." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119667.

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The forest transition occurring in developed countries, including northeastern North America and western Europe, led to an emergence of secondary forests that fueled research about past land-use legacies on biodiversity. Past land-use has been shown to lower plant species richness, especially that of forest herb species. A few studies have also considered landscape configuration around secondary forests, either in the present-day or during the early period of old field colonization. My study examines the effects of both past land-use and past landscape context on species composition and richne
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Heimann, Juliane [Verfasser], Wolfgang W. [Akademischer Betreuer] Weisser, Günter [Akademischer Betreuer] Köhler, and Klaus [Akademischer Betreuer] Reinhold. "Generalist insect herbivore performance in dependence of plant species richness, composition and quality / Juliane Heimann. Gutachter: Wolfgang W. Weisser ; Günter Köhler ; Klaus Reinhold." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2012. http://d-nb.info/1028799012/34.

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Shah, Parita Raj. "Evaluation of Digital PCR (dPCR) for the Quantification of Soil Nitrogen Turnover Bacteria in Wetland Mesocosms in Response to Season, Fertilization, and Plant Species Richness." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87580.

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Excess nutrients from nonpoint sources are an ongoing problem that is expected to worsen as population and fertilizer usage rise. Conventional centralized treatment systems are not well suited to address nonpoint source pollution. More distributed best management practices (BMPs) like constructed wetlands are a promising alternative and have been widely implemented in the US since the 1970's. Constructed wetlands are multi-functional systems that can effectively store and transform harmful contaminants using primarily natural processes. However, the removal of pollutants like nitrogen by wetla
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Lilley, Patrick Ledford. "Determinants of native and exotic plant species diversity and composition in remnant oak savannas on southeastern Vancouver Island." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/243.

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Many regional and local factors can influence the distribution of native and exotic species in ecological communities. I examined the regional- and local-scale determinants of native and exotic vascular plant species richness and composition in a highly fragmented oak savanna ecosystem on southeastern Vancouver Island. In sharp contrast to most reported results, I found a negative relationship between native and exotic richness at the regional scale, and no relationship at the local scale. Two extrinsic factors, surrounding road density and climate, best explained the regional-scale relationsh
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Schetter, Timothy Andrew. "A Multiscale Spatial Analysis of Oak Openings Plant Diversity with Implications for Conservation and Management." Bowling Green State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1334089503.

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Bergström, Elin. "Växtartrikedomens svar på restaurering av hävdade gräsmarker : En litteraturstudie." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-178830.

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En av de naturtyper med flest antal växtarter i världen är hävdade gräsmarker som är präglade av traditionell skötsel. Denna naturtyp har minskat kraftigt i area och för att förhindra framtida artutdöenden är restaureringsåtgärder viktiga. Syftet med denna rapport var att med hjälp av vetenskapliga publikationer undersöka vilken effekt restaurering av före detta hävdade gräsmarker i norra och centrala Europa har på växtartrikedomen. Mer specifikt undersöktes effekten av olika restaureringsmetoder på totala antalet arter, arttätheten och artsammansättningen. Utöver det
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Broshot, Nancy Ellen. "The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon." PDXScholar, 1999. https://pdxscholar.library.pdx.edu/open_access_etds/3962.

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The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, al
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Schmiedel, Inga Verfasser], Heike [Akademischer Betreuer] Culmsee, Erwin [Akademischer Betreuer] Bergmeier, et al. "Vascular plant species richness at the landscape scale: Patterns and processes / Inga Schmiedel. Gutachter: Erwin Bergmeier ; Christoph Leuschner ; Renate Bürger-Arndt ; Susanne Bögeholz ; Hermann Behling ; Markus Hauck. Betreuer: Heike Culmsee." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1072550598/34.

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Ström, Lotta. "Effects of climate change on boreal wetland and riparian vegetation." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-43811.

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Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. These changes will substantially alter the hydrology of rivers and streams and change the conditions for riverine communities. The warming is also expected to result in species adjusting their geographic ranges to stay within their climatic tolerances. Ripa
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Bagaria, Morató Guillem. "Time lags in plant community assembly after forest encroachment into Mediterranean grasslands: drivers and mechanisms." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/295705.

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La pèrdua, fragmentació i transformació dels hàbitats representen una gran amenaça per a la biodiversitat en els ecosistemes terrestres d'arreu del món, desencadenant tant extincions com colonitzacions amb un resultat incert en la composició i la riquesa d'espècies. Els retards de diverses dècades, coneguts com a deute d'extinció i crèdit de colonització, són habituals després dels canvis en els usos del sòl. No obstant, hi ha una manca d'estudis que abordin l'ensamblatge de comunitats tenint en compte tant el deute d'extinció pels especialistes de l'hàbitat previ com el crèdit de colonització
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Pajunen, A. (Anu). "Willow-characterised shrub vegetation in tundra and its relation to abiotic, biotic and anthropogenic factors." Doctoral thesis, University of Oulu, 2010. http://urn.fi/urn:isbn:9789514261138.

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Abstract Deciduous shrubs form the tallest type of vegetation in arctic-alpine areas and are important for ecosystem function. In the southern part of the Eurasian tundra zone, willows (Salix spp.) are the most common species in the shrub layer. In the alpine areas of Northern Fennoscandia, willow shrubs are characteristic to areas between tree line and treeless tundra heaths. Vertical structure and composition of willow-characterized tundra vegetation is affected by a variety of ecological factors including climate and herbivory. In turn, the abundance of the willow canopy affects understory
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Orihuela, Rodrigo Leonel Lozano. "Diversidade e abundância de hemiepífitos em um gradiente altitudinal na Floresta Atlântica no Sul do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/26288.

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O objetivo principal deste trabalho foi identificar os principais fatores abióticos e bióticos correlacionados com a distribuição da abundância e riqueza de hemiepífitos primários, secundários e lianas rizo-escandentes, sinúsias que carecem de estudos, em um gradiente altitudinal na Floresta Atlântica sul-brasileira. Alocamos 15 unidades amostrais no total (de 400 m2 cada), distribuídas nas porções inferior (200 - 250 m a.n.m.), média (380 - 430 m) e superior (670 - 720 m) de um gradiente altitudinal no nordeste do Rio Grande do Sul. Amostramos em cada parcela a abundância de cada espécie, a p
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45

Bedecarrats, Alain. "Les peuplements végétaux issus de l'ensemencement des pistes de ski dans les Alpes du Nord : structure et dynamisme." Grenoble 1, 1988. http://www.theses.fr/1988GRE10071.

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Les groupements issus de l'enherbement au moyen de melanges de graines de varietes d'especes herbacees commercialisees (dont principalement festuca rubra, festuca ovina, phleum pratense, lolium perenne, trifolium repens, trifolium hybridum, lotus corniculatus) des zones terrassees lors de la construction des pistes de ski evoluent tres rapidement en fonction des configurations des milieux. Leur etude dans les domaines du montagnard superieur a l'alpin inferieur sur des terrains pauvres en calcium et a bon equilibre textural situes aux menuires et a val thorens en savoie fait ressortir: que jus
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Lindgren, Jessica. "Small remnant habitats : Important structures in fragmented landscapes." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148653.

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The world-wide intensification of agriculture has led to a decline in species richness due to land use change, isolation, and fragmentation of natural and semi-natural habitats in agricultural and forestry landscapes. As a consequence, there is a current landscape management focus on the importance of green infrastructure to mitigate biodiversity decline and preserve ecosystem functions e.g. pollination services and pest control. Even though intensification in agriculture has been ongoing for several hundreds of years, remnant habitats from earlier management practices may still be remaining w
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Li, Yuanzhi. "Structure et dynamique d'occupation de l'espace fonctionnel à travers des gradients spatiaux et temporels." Thèse, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/11615.

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Les modèles d'occupation de niche au sein des communautés locales, la variabilité spatiale de la biodiversité le long des gradients environnementaux du stress et des perturbations, et les processus de succession végétale sont plusieurs sujets fondamentaux en écologie. Récemment, l'approche basée sur les traits est apparue comme un moyen prometteur de comprendre les processus structurant les communautés végétales et cette approche a même été proposée comme méthode pour reconstruire l'écologie communautaire en fonction des traits fonctionnels. Par conséquent, lier ces thèmes fondamentaux en util
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Köchy, Martin, and Sven Bråkenhielm. "Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs." Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2008/1662/.

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The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7–13 kg ha−1 year−1) and lower bulk N deposition (4–6 kg ha−1 year−1) in southern Sweden during 1982–1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cov
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Aksamit, Dawn N. "Exotic Invasive Plants on Private Woodlands of Virginia: Effects on forest composition, structure, and wildlife habitat." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/30975.

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Exotic invasive plants have become a significant issue in the Southeastern United States for private landowners. These plants possess characteristics that allow for rapid growth and easy adaptation to many growing conditions, often outcompeting native vegetation and altering wildlife habitat, especially in disturbed areas. Disturbance, including access roads, trails, harvest sites, powerline corridors, and fence rows, is common on private land. Private landowners are often left to combat these problems without many monetary or expertise resources that are available to federal lands. Three
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Guthrie, Ruth J. "Patterns of invertebrate distribution and abundance on Cordyline australis in human-modified landscapes." Diss., Lincoln University, 2008. http://hdl.handle.net/10182/1235.

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Fragmentation of forest habitat by urban and rural development has had profound effects on the distribution and abundance of many native species; however, little is known about the ecological processes driving patterns in community structure (species richness and composition) of host-specialised herbivores in modified habitats. I examined patterns in community structure of 9 specialist and 19 generalist invertebrate herbivores of cabbage trees (Cordyline australis Laxmanniaceae) across a highly-modified landscape. I found that, although species richness of specialists was highest in forest sit
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