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Bat species richness and activity in forest habitats close to lakes versus far from lakes, in SwedenZuniga, Silvia January 2013 (has links)
The long-term effects of large-scale changes in forestry, agriculture and other land use on habitats and the large-scale expansion of wind farming affects bats foraging environments. In order to predict consequences of exploitations on local bat species and populations, good surveys are important. To get good background information for an Environmental Impact Assessment (EIA) it is crucial to rapidly assess which areas are most important for bats. The aim of this work was to measure the importance of the two types of forest environment for bats foraging : forest areas located close to or far from the lakes. Bat activity and species diversity was measured with automatic ultrasound recorders in 211 nights of fieldwork at 155 locations in 23 areas in different parts of Sweden during June, July and the first two weeks of August 2011 and 2012. A total of 11 species were recorded in forest far from lakes and 8 species in forest close to lakes. Eptesicus nilssonii , Myotis sp. and Pipistrellus pygmaeus were the most common taxa in both habitat types. Activity levels were higher in the vicinity of lakes compared to forests far away from lakes. Species diversity calculated on base on Chao 2 was similar for both types of habitats . The results suggest that the forests close to lakes are the most important habitats to surveys for bats in Sweden and that inventory efforts should be primarily invested in them.
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The Anoplotermes group in French Guiana: Systematics, Diversity and EcologyBourguignon, Thomas 28 May 2010 (has links)
Les termites forment un groupe animal important en milieu tropical, où leur richesse spécifique est plus élevée que dans n’importe quel autre écosystème. Ils se nourrissent de matière organique végétale à différent état de décomposition, du bois dur à la matière organique minérale du le sol. Cette diversification du régime alimentaire ne se produit que chez les Termitidae, parfois appelés « termites supérieurs », alors que les autres familles se nourrissent exclusivement de bois ou d’herbe. Les termites humivores sont extrêmement abondants en Amérique du Sud et en Afrique tropicale, mais sont relativement peu étudiés par rapport aux termites xylophages. C’est particulièrement vrai pour le groupe Anoplotermes, qui représente le groupe de termites le moins bien connu. Ce travail vise à faire la lumière sur l’écologie et la diversité de ce groupe strictement humivore, et comprend les sections suivantes : (1) Des échantillonnages standardisés dans sept sites de Guyane Française ont révèle, avec quelques exceptions, que les termites xylophages sont relativement peu spécialisés à un site. Au contraire, les espèces du groupe Anoplotermes, ainsi que les termites humivores en général, sont spécialisés à un type de forêt. Cette spécialisation contribue plus que probablement à la diversification écologique, et donc, à une augmentation de la richesse spécifique des termites humivores. (2) En utilisant les ratios d’isotopiques δ13C et δ15N, nous avons aussi trouvé qu’il existe une spécialisation des espèces le long d’un gradient d’humification chez le groupe Anoplotermes, de l’interface entre le bois pourri et le sol au sol pauvre en matière organique. Donc, au moins deux facteurs favorisent la richesse spécifique du groupe Anoplotermes dans le sol, malgré le manque d’évidence pour une séparation spatiale et temporelle entre les espèces. Cette spécialisation spécifique réduit la compétition interspécifique aux espèces se nourrissant de matière organique au même état de décomposition. (3) Ce mécanisme n’est probablement pas restreint aux espèces du groupe Anoplotermes et le ratio isotopique δ15N varie considérablement entre les termites humivores de manière générale. Les termites humivores comptent des espèces avec des régimes alimentaires différents ne partageant pas toujours les mêmes niches écologiques. Cette diversification du régime alimentaire ne c’est pas produit de manière aléatoire durant l’évolution des termites et les espèces proches tendent à se nourrir du même substrat. (4) Au niveau intraspécifique, il semble que la compétition contraigne la dynamique des colonies. En effet, chez A. banksi, nous avons trouvé que les nids matures sont surdispersés. Les nouveaux nids se trouvent principalement à une certaine distance des nids établis, plus particulièrement dans les trous laissés par les nids morts. Si ce patron est le résultat d’une sélection des sites de nidification, ou plutôt d’une exclusion compétitive reste sujet à discussion, mais met néanmoins en évidence la présence de compétition chez les termites humivores du groupe Anoplotermes. (5) Au vu de la richesse spécifique locale du groupe Anoplotermes, le nombre d’espèces décrites reste remarquablement bas. Après inspection du matériel type, seuls 30 espèces du groupe se sont avérés valides en Amérique du Sud, alors que 80% des espèces que nous avons collectées sont nouvelles pour la science. Cette disproportion entre ce qui est connu et la diversité réelle du groupe, met en évidence le besoin de réaliser des études supplémentaires pour améliorer la connaissance de ce groupe peu connu, le groupe Anoplotermes.
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The Biogeography of Peel's Urban Forest: Patterns and Correlates of Species DiversityBourne, Kirstin 11 August 2011 (has links)
The purpose of this research project is to identify the species-level diversity and distribution of trees within the urban setting of Peel Region (Ontario, Canada) and to determine how these characteristics change as a function of land use type. To address this, alpha diversity (species richness within a community), evenness, and beta diversity (species richness between communities) were calculated for eight distinct land use types within the study area. As well, the influence that a variety of socioeconomic and urban form variables have in determining urban forest composition was examined using regression techniques. Results indicate that significant relationships exist between land use type, species richness and overall tree abundance. Variables reflecting wealth and urban form are also shown to significantly influence tree abundance. The results of this study address issues pertaining to the adaptation, conservation, and management of the region’s urban tree species.
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The Biogeography of Peel's Urban Forest: Patterns and Correlates of Species DiversityBourne, Kirstin 11 August 2011 (has links)
The purpose of this research project is to identify the species-level diversity and distribution of trees within the urban setting of Peel Region (Ontario, Canada) and to determine how these characteristics change as a function of land use type. To address this, alpha diversity (species richness within a community), evenness, and beta diversity (species richness between communities) were calculated for eight distinct land use types within the study area. As well, the influence that a variety of socioeconomic and urban form variables have in determining urban forest composition was examined using regression techniques. Results indicate that significant relationships exist between land use type, species richness and overall tree abundance. Variables reflecting wealth and urban form are also shown to significantly influence tree abundance. The results of this study address issues pertaining to the adaptation, conservation, and management of the region’s urban tree species.
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Diversity of birds in relation to area, vegetation structure and connectivity in urban green areas in La Paz, BoliviaHiding, Camilla January 2012 (has links)
With a growing human population, cities keep growing worldwide altering ecosystem and thereby affecting the species living in these areas. Most studies of urbanization and its effect on ecosystem have been conducted in the western world and little is known about its effect in the neotropical part of the world. I examined effects of fragment size, vegetation structure and connectivity of urban green areas on bird species richness, mean abundance, diversity and biomass in La Paz, Bolivia. Additionally, the effects of different disturbance variables on bird community were evaluated. In total, 36 bird species were found in 24 fragment of varying size, connectivity and level of disturbance. Bird species richness decreased with increasing disturbance while connectivity and fragment size did not contribute significantly to explain the variation in species richness at count point scale (p>0.005, multiple linear regression). At fragment scale, however, species richness increased with fragment sizes, which has been shown in other studies from neotrophical regions. Variation in abundance, diversity or biomass could not be explained by connectivity, fragment size or disturbance. Furthermore, coverage of construction had a negative effect on species richness while coverage of bushes and coverage of herbs were negatively related to biomass and diversity, respectively. The composition of bird species differed with size and disturbance of the fragments, so that more omnivorous and granivorous species such as Zonotrichia capensis, Turdus chiguanco and Zenaida auriculata, were present in areas highly affected by human activities. Larger fragments, less affected by human presence held a larger proportion of insectivorous species.
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A Study of Plant Species Richness in Taiwan Forestry Research Institute Tai-Ma-Lee Experimental ForestTzi, Ting-Yi 21 July 2005 (has links)
Many ecologists are struggling to quantify the species richness in a particular landscape or region. The number of species increases with sample area. Species-area relationship is often used to estimate species richness of a particular region. This study used species-log (area) curves, corrected with Jaccard¡¦s coefficients for within-vegetation type heterogeneity, to estimate species richness and to describe vascular plant species composition in Taiwan Forestry research Institute Tai-Ma-Lee Experimental Forest.
In the study area, the author recorded 748 plant species, including 98 endemic species, 21 rare species and 36 naturalized species.
There are estimation of 701 species (95¢H CI¡×651~758 species) in the 583-ha natural forest area, 819 species (95¢H CI¡×744~889 species) in the 291-ha plantation area, 560 species (95¢H CI¡×508~641 species) in 8.1-ha forest road. As plantation area is not well-sampled, the total species number in the 947-ha study area could not be estimated. When use 0.1 Modified-Whittaker sampling techniques to assess plant diversity, it is possible to use elevation division, instead of vegetation type, to estimate species richness.
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Adaptive Diversification of Interaction NetworksStegen, James January 2009 (has links)
Understanding the processes responsible for gradients in biodiversity is a central goal of ecological research. In order to elucidate the processes responsible for community assembly and structure, it is useful to adopt a functional trait approach to community ecology. This is because species names provide little information regarding how constituent species interact. In addition, assembly rules based on species names are likely to become intractably complex with increasing species richness but rules based on traits can provide simple, broadly applicable. In turn, generality is gained by emphasizing functional traits. Here I first build from a previously published model that merged metabolic theory with a model of community evolution and assembly to derive a general assembly rule based on a continuous functional trait and compare this rule with a broad suite of empirical data (Chapter 1). However, linking metabolism to macroevolutionary rates and patterns has thus far been limited to non-ecological, static models. These models are not inconsistent with empirical data, but are relatively limited in their predictive ability (Chapter 2). I thus next develop a fully dynamic `metabolic theory of biodiversity' (MTB) that explicitly implements the qualitative framework proposed in Allen et al. (2007). With this model I examine the influence of temperature dependent mutation rate on speciation rate, extinction rate and species richness (Chapter 2). The model predicts a variable influence of temperature, but the processes responsible for this variation are not immediately clear. I subsequently conduct a detailed analysis elucidating the key processes that allow/constrain a strong influence of temperature dependent mutation rate on species richness (Chapter 3). In addition to mutation rate, temperature-dependent metabolism can influence ecological (feeding and mortality) and ecosystem (e.g. decomposition and in turn nutrient supply) rates. As such, I extend the model developed in chapters 1-3 to incorporate these additional temperature dependencies and derive predictions for the influence of temperature over species richness (Chapter 4).
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Exploring Species Diversity and Molecular Evolution of Arachnida through DNA BarcodesYoung, Monica Rose 11 February 2013 (has links)
This thesis investigates species diversity and patterns of molecular evolution in Arachnida through DNA barcoding. The first chapter assesses mite species richness through comprehensive sampling at a subarctic location in Canada. Barcode analysis of 6279 specimens revealed nearly 900 presumptive species with high rates of turnover between major habitat types, demonstrating the utility of DNA barcoding for biodiversity surveys of understudied taxa. The second chapter explores nucleotide composition, indel occurrence, and rates of amino acid evolution in Arachnida. The results suggest a significant shift in nucleotide composition in the arachnid subclasses of Pulmonata (GC = 37.0%) and Apulmonata (GC = 34.2%). Indels were detected in five apulmonate orders, with deletions being much more common than insertions. Finally, rates of amino acid evolution were detected among the orders, and were negatively correlated with generation length, suggesting that generation time is a significant contributor to variation in molecular rates of evolution in arachnids.
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A bryophyte perspective on forest harvest: The effects of logging on above- and below-ground bryophyte communities in coastal temperate rainforestsMiyashita, Kesia A. Unknown Date
No description available.
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Influence of landscape scale and habitat distribution on individual bat species and bat species richnessBrüsin, Martin January 2013 (has links)
Habitat fragmentation is one of the most important factors affecting species extinction and biodiversity loss, Species habitat response expects to differ with habitat feature at different spatial scales and this study was to identify how bat diversity and individual bat species respond to different habitat amounts. The local bat species richness was observed in 156 different locations in Östergötland and the proportion of different habitats were calculated for circular areas with diameters ranging from 400 m. to 12 km. from each location. Although we found that the individual bat species responded differently to the amount of each habitat at different spatial scales, the bat species richness showed a decreasing response with increasing spatial scale. The strongest response of bat species richness to habitat characteristics was at a scale of 939 m.
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