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2012

Species richness

Articles 1 - 10 of 10

Full-Text Articles in Life Sciences

Local Filters Limit Species Diversity, But Species Pools Determine Composition, Tara K. Rajaniemi, Deborah E. Goldberg, Roy Turkington, Andrew R. Dyer Dec 2012

Local Filters Limit Species Diversity, But Species Pools Determine Composition, Tara K. Rajaniemi, Deborah E. Goldberg, Roy Turkington, Andrew R. Dyer

Faculty Publications

In a series of three experiments, we tested for effects of species pools, resource stress, and species interactions on four aspects of community structure: species richness, evenness, species composition, and functional group composition. We also examined whether the impacts of species interactions on the community varied with resource availability or species pool. Communities of sand dune annuals grew from seed bank samples collected from two sites in three different years, so that the species pool differed at two levels: the source site and the year of seed bank collection. Communities experienced one of three irrigation treatments and a range of …


A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin Dec 2012

A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin

Theses and Dissertations

An intensive sampling of all ant species encountered on 6 Hawaiian Islands: Big Island, Maui, Oahu, Kauai, Molokai, and Lanai took place between 1988 and 1996. Species presence and absence was recorded at each site. Using remote sensing, variables were added insitu and used throughout my analysis. Species accumulation curves suggest that sampling was comprehensive. There is a significant trend between island area and species richness which validates the Theory of Island Biogeography for invasive species. Islands were found to be significantly nested by area, order, and tourism. Cluster analysis shows a link between elevation, land-use and island, and species …


Avian Diversity And Habitat Use On Wetland Reserve Program Lands In The Lower Missouri River Valley, Eric C. Hopps Dec 2012

Avian Diversity And Habitat Use On Wetland Reserve Program Lands In The Lower Missouri River Valley, Eric C. Hopps

The Prairie Naturalist

A primary objective of the Wetland Reserve Program (WRP) is to provide habitat for migratory birds throughout all seasons of the year. Comprehensive avian assessments are lacking and limit our ability to evaluate the benefits of the WRP to continental bird populations. I investigated avian species occurrence on WRP lands within the Lower Missouri River Valley (LMRV), Nebraska, USA, from March 2010 to February 2011. Ten WRP habitat types are described based on plant community assemblages and observed hydrological regimes. Estimates of avian species richness were greatest in lowland forest (n = 115), lowland woodland (n = 83) and upland …


Intraspecific Density Dependence And A Guild Of Consumers Coexisting On One Resource, Mark A. Mcpeek Dec 2012

Intraspecific Density Dependence And A Guild Of Consumers Coexisting On One Resource, Mark A. Mcpeek

Dartmouth Scholarship

The importance of negative intraspecific density dependence to promoting species coexistence in a community is well accepted. However, such mechanisms are typically omitted from more explicit models of community dynamics. Here I analyze a variation of the Rosenzweig-MacArthur consumer–resource model that includes negative intraspecific density dependence for consumers to explore its effect on the coexistence of multiple consumers feeding on a single resource. This analysis demonstrates that a guild of multiple consumers can easily coexist on a single resource if each limits its own abundance to some degree, and stronger intraspecific density dependence permits a wider variety of consumers to …


Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas Oct 2012

Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas

Biology Faculty Publications

We characterized soil communities in the Mojave Desert across an elevation gradient. Our goal was to test the hypothesis that as soil quality improved with increasing elevation (due to increased productivity), the diversity of soil prokaryotes and nematodes would also increase. Soil organic matter and soil moisture content increased with elevation as predicted. Soil salinity did not correlate to elevation, but was highest at a mid-gradient, alluvial site. Soil nematode density, community trophic structure, and diversity did not show patterns related to elevation. Similar results were obtained for diversity of bacteria and archaea. Relationships between soil properties, nematode communities, and …


Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries Sep 2012

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Frank S. Gilliam

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …


The Relationship Between Live Coral And Macroalgae In South Caicos As Influenced By Herbivorous Fishes, Sarah Byce Apr 2012

The Relationship Between Live Coral And Macroalgae In South Caicos As Influenced By Herbivorous Fishes, Sarah Byce

Honors Theses

Marine life is the basis for most industries in the Turks and Caicos Islands, located on the outskirts of the Caribbean Sea. Few studies have been carried out to assess the current status of reefs in this region, especially those off the shore of South Caicos Island. The AGRRA v.4.0 methodologies were employed create baseline assessments of stony corals, macroalgae and associated fishes and to explore the relationships between these key reef organisms. This study was based on 10 different locations both inside and outside of Marine Protected Areas (MPAs) and including exposed and sheltered reefs in proximity to South …


Bird Red List And Its Future Development In Mongolia, Sundev Gombobaatar, D. Samiya, Jonathan M. Baillie Jan 2012

Bird Red List And Its Future Development In Mongolia, Sundev Gombobaatar, D. Samiya, Jonathan M. Baillie

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

With the involvement of the World Bank, Zoological Society of London, Dutch Government and National University of Mongolia, the volumes of Mongolian Red Lists of Fish, Amphibians and Reptiles, Birds and Mammals were completed, and Mongolia is now among the few nations that have up-to-date conservation assessments for all vertebrates. Of the 476 assessed native bird species of Mongolia, 10% were categorized as regionally threatened including Near Threatened. A further 0.6% were categorized as Critically Endangered (CR), 1.7% as Endangered (EN), 3.3% as Vulnerable (VU), and 4.4% as Near Threatened (NT). Almost 90% of Mongolian birds are categorized as Least …


Modeling Broad-Scale Patterns Of Avian Species Richness Across The Midwestern United States With Measures Of Satellite Image Texture, Patrick D. Culbert, Volker C. Radeloff, Véronique St-Louis, Curtis H. Flather, Chadwick D. Rittenhouse, Thomas P. Albright, Anna M. Pidgeon Jan 2012

Modeling Broad-Scale Patterns Of Avian Species Richness Across The Midwestern United States With Measures Of Satellite Image Texture, Patrick D. Culbert, Volker C. Radeloff, Véronique St-Louis, Curtis H. Flather, Chadwick D. Rittenhouse, Thomas P. Albright, Anna M. Pidgeon

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Avian biodiversity is threatened, and in order to prioritize limited conservation resources and conduct effective conservation planning a better understanding of avian species richness patterns is needed. The use of image texture measures, as a proxy for the spatial structure of land cover and vegetation, has proven useful in explaining patterns of avian abundance and species richness. However, prior studies that modeled habitat with texture measures were conducted over small geographical extents and typically focused on a single habitat type. Our goal was to evaluate the performance of texture measures over broad spatial extents and across multiple habitat types with …


Do Species Distribution Models Predict Species Richness In Urban And Natural Green Space? A Case Study Using Amphibians, Joseph Milanovich, William E. Peterman, Kyle Barrett, Matthew Hopton Jan 2012

Do Species Distribution Models Predict Species Richness In Urban And Natural Green Space? A Case Study Using Amphibians, Joseph Milanovich, William E. Peterman, Kyle Barrett, Matthew Hopton

Biology: Faculty Publications and Other Works

No abstract provided.