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Biodiversity

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Articles 151 - 180 of 201

Full-Text Articles in Biology

Biodiversity Assessment And Its Effect On The Environment Of Shakarparian Forest, Inayat Ullah Malik, Abul Hasan Faiz, Fakhar -I- Abbas Nov 2014

Biodiversity Assessment And Its Effect On The Environment Of Shakarparian Forest, Inayat Ullah Malik, Abul Hasan Faiz, Fakhar -I- Abbas

Journal of Bioresource Management

Shakarparian is known for its scenic beauty and wilderness and has a significant recreational value. It is a part of Margalla Hills National Park (MHNP), Islamabad and can be a good recourse to conduct various environmental studies. This study was aimed to explore the overall biodiversity of Shakarparian forest in terms of flora and its associated fauna. Phytosociological survey was carried out in order to identify the existing plant communities. The plant associations were then correlated to the existing fauna of the area. The results will provide the baseline data to support further studies on biodiversity analysis of ecologically rich …


Effect Of Grain, Region, And Human Influence On Higher Taxonomic Surrogacy, Frances Owen Nov 2014

Effect Of Grain, Region, And Human Influence On Higher Taxonomic Surrogacy, Frances Owen

Master's Theses or Doctor of Nursing Practice

Surrogacy is a common tool within conservation and can be useful when scientists lack detailed knowledge of a system. Higher taxonomic surrogacy is appealing because it can save time and money. However, this technique might vary in effectiveness depending on the taxonomic level, spatial grain, region, and impact by humans. In this thesis I addressed some of the common concerns with higher taxonomic surrogacy using Breeding Bird Atlas data from six states (Colorado, Florida, Michigan, New York, Pennsylvania, and Washington). I compared the coefficients (slopes) of my models rather than the R2 values relied on by other higher taxonomic surrogacy …


Height And Clonality Traits Determine Plant Community Responses To Fertilization, Timothy L. Dickson, Gary G. Mittelbach, Heather L. Reynolds, Katherine L. Gross Sep 2014

Height And Clonality Traits Determine Plant Community Responses To Fertilization, Timothy L. Dickson, Gary G. Mittelbach, Heather L. Reynolds, Katherine L. Gross

Biology Faculty Publications

Fertilization via agricultural inputs and nutrient deposition is one of the major threats to global terrestrial plant richness, yet we still do not fully understand the mechanisms by which fertilization decreases plant richness. Tall clonal species have recently been proposed to cause declines in plant species richness by increasing in abundance in response to fertilization and competing strongly with other species. We tested this hypothesis in a fertilization experiment in a low productivity grassland by using a novel experimental manipulation of the presence vs. absence of clonal species and by examining the role of height within these treatments. We found …


Biodiversity And Distribution Of Entomophilic Nematodes In Utah’S Mojave Region, Westen Archibald, Dr. Byron Adams Apr 2014

Biodiversity And Distribution Of Entomophilic Nematodes In Utah’S Mojave Region, Westen Archibald, Dr. Byron Adams

Journal of Undergraduate Research

To better understand the diversity and distribution of entomophilic nematodes in Utah’s Mojave region, I have begun a project that’s purpose is to develop phylogenetic maps of 55 nematode species that I have already extracted from the soils of the Beaver Dam wash ecotone. This project involves both the reconstruction of evolutionary relationships to recover biodiversity, and generating a species distribution map for the Beaver Dam wash ecotone.


The Role Of Landscape Variation In Shaping The Evolutionary Diversification Of Chimpanzees (Pan Troglodytes) In A Biodiversity Hotspot, Matthew William Mitchell Jan 2014

The Role Of Landscape Variation In Shaping The Evolutionary Diversification Of Chimpanzees (Pan Troglodytes) In A Biodiversity Hotspot, Matthew William Mitchell

Legacy Theses & Dissertations (2009 - 2024)

In this dissertation, I combine population genetic and demographic history analyses of autosomal, mitochondrial and Y-chromosome genetic markers with spatially explicit modeling techniques to study the biogeographic mechanisms responsible for shaping patterns of genetic diversity among chimpanzees in Cameroon and eastern Nigeria. I also describe a new software tool, TESS Ad-Mixer, that I developed early on in this study to help visualize the geographic distribution of demes recovered from population cluster analyses.


Opiliones Biodiversity In Cusuco National Park, Honduras, Brittany N. Damron Jan 2014

Opiliones Biodiversity In Cusuco National Park, Honduras, Brittany N. Damron

Browse all Theses and Dissertations

Biodiversity in the tropics is especially diverse and describing species found in the tropics is important. Opiliones species richness is higher in the tropics than the temperate zone, with diversity highest in low latitudes. This study aims to catalog the Opiliones community in Cusuco National Park, Honduras, while estimating species richness and describing their abundance, distribution and community structure. Fifty hours of sampling at 6 sites yielded 18 morphospecies and 264 individual Opiliones were collected. This study added one new described species to the Opiliones fauna of Honduras, and fourteen morphospecies may represent new species. An estimated 43 to 112 …


La Diversidad De Los Análisis De Diversidad La Diversidad De Los Analisis De Diversidad [The Diversity Of Diversity Analyses], Victor D. Carmona-Galindo, Tizziana V. Carmona Dec 2013

La Diversidad De Los Análisis De Diversidad La Diversidad De Los Analisis De Diversidad [The Diversity Of Diversity Analyses], Victor D. Carmona-Galindo, Tizziana V. Carmona

Biology Faculty Works

There is a lack of consistency with respect to the use of the terms like species richness, diversity and biodiversity, which extends to the analysis of diversity indices and the merit of using diversity indices in the evaluation (comparison and contrast) of biological communities. The purpose of this article is to provide working definitions for these terms and cite examples from the primary literature that demonstrate the utility of estimating richness, evaluating proportional abundance patterns, as well as comparing indices of diversity and similarity to study patterns of biological organization at different ecological scales. Additionally, we provide a manual in …


The Crayfish Identity Crisis: A Morphological And Genetic Assessment Of Biodiversity, Matthew R. Carpenter, Dr. Keith A. Crandall Oct 2013

The Crayfish Identity Crisis: A Morphological And Genetic Assessment Of Biodiversity, Matthew R. Carpenter, Dr. Keith A. Crandall

Journal of Undergraduate Research

Among the most endangered animal groups of North America is the freshwater crayfish. Their survival has been hindered by rapid growth in the human population, water pollution, and habitat degradation. The American Fisheries Society has estimated that 50% of freshwater crayfishes are in need of conservation measures (Taylor et al. 1996). However, only 1% is currently protected under the Endangered Species Act of 1973. Because crayfish are at the center of invaluable research as top predators, nutrient recyclers, and bio-indicators of our water quality, it is important that conservation measures are taken.


A Multi-Scale Analysis Of The Effects Of Local- And Landscape-Level Variables On Nuthatch Occupancy And Distribution, Jesse Wood Oct 2013

A Multi-Scale Analysis Of The Effects Of Local- And Landscape-Level Variables On Nuthatch Occupancy And Distribution, Jesse Wood

Earth and Environmental Sciences Presentations

The objectives of this study are to conduct a multi-scale analysis of the effects of habitat variables on Brownheaded Nuthatch (S. pusilla) occupancy and spatial distribution in the greater Greenville area of South Carolina. By understanding the local- and landscape-drivers of an ecologically sensitive species, we can build a predictive model of species occurrence and contribute to regional conservation efforts of both habitat and biodiversity.


Four Decades Of Andean Timberline Migration And Implications For Biodiversity Loss With Climate Change, David A. Lutz, Rebecca L. Powell, Miles R. Silman Sep 2013

Four Decades Of Andean Timberline Migration And Implications For Biodiversity Loss With Climate Change, David A. Lutz, Rebecca L. Powell, Miles R. Silman

Dartmouth Scholarship

Rapid 21st-century climate change may lead to large population decreases and extinction in tropical montane cloud forest species in the Andes. While prior research has focused on species migrations per se, ecotones may respond to different environmental factors than species. Even if species can migrate in response to climate change, if ecotones do not they can function as hard barriers to species migrations, making ecotone migrations central to understanding species persistence under scenarios of climate change. We examined a 42-year span of aerial photographs and high resolution satellite imagery to calculate migration rates of timberline–the grassland-forest ecotone–inside and outside of …


Opposing Mechanisms Drive Richness Patterns Of Core And Transient Bird Species, Jessica R. Coyle, Allen H. Hurlbert, Ethan P. White Apr 2013

Opposing Mechanisms Drive Richness Patterns Of Core And Transient Bird Species, Jessica R. Coyle, Allen H. Hurlbert, Ethan P. White

Biology Faculty Publications

Studies of biodiversity typically assume that all species are equivalent. However, some species in a community maintain viable populations in the study area, while others occur only occasionally as transient individuals. Here we show that North American bird communities can reliably be divided into core and transient species groups and that the richness of each group is driven by different processes. The richness of core species is influenced primarily by local environmental conditions, while the richness of transient species is influenced primarily by the heterogeneity of the surrounding landscape. This demonstrates that the well-known effects of the local environment and …


Estimated Losses Of Plant Biodiversity Across The U.S. From Historical N Deposition From 1985—2010., Christopher M. Clark, Philip E. Morefield, Frank S. Gilliam, Linda H. Pardo Feb 2013

Estimated Losses Of Plant Biodiversity Across The U.S. From Historical N Deposition From 1985—2010., Christopher M. Clark, Philip E. Morefield, Frank S. Gilliam, Linda H. Pardo

Biological Sciences Faculty Research

Although nitrogen (N) deposition is a significant threat to herbaceous plant biodiversity worldwide, it is not a new stressor for many developed regions. Only recently has it become possible to estimate historical impacts nationally for the United States. We used 26 years (1985–2010) of deposition data, with ecosystem-specific functional responses from local field experiments and a national critical loads (CL) database, to generate scenario-based estimates of herbaceous species loss. Here we show that, in scenarios using the low end of the CL range, N deposition exceeded critical loads over 0.38, 6.5, 13.1, 88.6, and 222.1 million ha for the Mediterranean …


Arthropod Abundance And Diversity In Street Trees Of South Texas, Usa, Alexis Racelis, Ann T. Vacek, Carol Goolsby, John Brush, John A. Goolsby Jan 2013

Arthropod Abundance And Diversity In Street Trees Of South Texas, Usa, Alexis Racelis, Ann T. Vacek, Carol Goolsby, John Brush, John A. Goolsby

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

In urban areas, street trees provide a variety of ecological services, including biodiversity conservation. In this study we examined arthropod diversity on native and non-native street trees sampled during the fall of 2010 and spring of 2011 in McAllen, Texas, one of the most rapidly growing urban areas in the country. Eighty-eight street trees were sampled by removing arthropods from the lower canopy foliage using a hand held vacuum. Arthropods were collected into nylon bags, identified to order, and counted by morphospecies. Overall, street trees supported a significant and diverse population of arthropods: a total of 1,971 arthropods were collected, …


Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker Dec 2012

Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker

Dissertations

Marine fungi are an important but often overlooked component of marine ecosystems. Primarily saprotrophic, they are vital to coastal nutrient cycling processes and food webs. However, basic marine fungal distribution data are lacking in many parts of the world, as is knowledge of the sampling intensity required to characterize the biodiversity of these communities. The roles of substrate, season and latitude in shaping intertidal ascomycete community structure were examined for the U.S. Gulf of Mexico, and the role of sampling frequency on species richness estimates was also addressed. Best sampling practices were developed and 750 collections of beach detritus, sand …


Transcendental Thermodynamics, Richard E. Morel, George Fleck Jun 2012

Transcendental Thermodynamics, Richard E. Morel, George Fleck

Kahn Institute Projects

Thermodynamics is often viewed as a narrow, introspective discipline, trapped by its origins in the 18th and 19th centuries. By dramatic contrast, we show that the Fourth Law of Thermodynamics provides explanations and interpretations of all natural events, extending across artificial boundaries of tradition- al academic disciplines. The Fourth Law of Thermodynamics states that far-from-equilibrium systems increase entropy at the maximum rate available to them. This broadly inclusive paradigm applies to systems from molecules, to organisms, to the biosphere. The Fourth Law is the Law of Evolution. All systems that communicate with their environment exhibit self-organization and self-optimization, enabling the …


Devil In A Hula Skirt: Comparative Conservation Efforts Between The United States And Australia Using Two Endemic Species As Case Studies, Sarah Catherine Kuchinsky May 2012

Devil In A Hula Skirt: Comparative Conservation Efforts Between The United States And Australia Using Two Endemic Species As Case Studies, Sarah Catherine Kuchinsky

Undergraduate Honors Thesis Collection

There is a biodiversity crisis in our midst. An abundance of technology and innovation in the last 200 years has revamped our world but at the cost of pushing many species to extinction. Since the passing of the Endangered Species Act by Congress in 1973, more than 100 species in the United States have disappeared (Wilson 2006). The International Union for the Conservation of Nature (IUCN) stats that "19,265 species out of the 59,507 so far assessed as threatened with extinction," (IUCN 2011). Extinction is the result of a combination of factors caused by human environmental disturbance. Disturbances in the …


Spatial Conservation Prioritization Of Kansas For Terrestrial Vertebrates, Megan R. Rohweder May 2012

Spatial Conservation Prioritization Of Kansas For Terrestrial Vertebrates, Megan R. Rohweder

Master's Theses or Doctor of Nursing Practice

Biological diversity is being threatened by the encroachment of humans, which limits the habitat available for conservation and strains resources allocated for conservation efforts. However conservation goals have to be achieved within these limitations. Conservation priorities can ensure that habitat and resources are used effectively and efficiently. I developed a conservation prioritization plan for the terrestrial vertebrates of Kansas. I used modeled distributions of every terrestrial vertebrate species found in Kansas to build three biodiversity indices; species richness, vulnerability, and endemicity. Kansas was divided into a grid of planning units, 34.5 km2. For each taxonomic group the planning units were …


Species And Habitat Interactions Of The Gopher Tortoise: A Keystone Species?, Christopher Catano Jan 2012

Species And Habitat Interactions Of The Gopher Tortoise: A Keystone Species?, Christopher Catano

Electronic Theses and Dissertations

Species-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their communities and habitats have rarely been empirically quantified. I examined how habitat structure influences tortoise abandonment of burrows and how tortoise densities influence nonvolant vertebrate community diversity. Tortoise burrow abandonment …


Agriculture In New York State : Farm Size And Its Implications To Farmland Protection And Biodiversity Conservation, Julianna Marie Potter Jan 2012

Agriculture In New York State : Farm Size And Its Implications To Farmland Protection And Biodiversity Conservation, Julianna Marie Potter

Legacy Theses & Dissertations (2009 - 2024)

In the United States there are 939 million acres of land held by ranchers and farmers. Conservation of this agricultural landscape is critical to the protection of biodiversity. Management of agricultural land is also associated with the success of biodiversity protection efforts in protected areas, including parks and preserves, as well as outside protected areas. Sustained viability of the New York farming sector will enhance and secure biodiversity on farmland, as viable farms will remain part of the landscape.


Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo Jan 2012

Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo

Open Access Theses & Dissertations

Leptopelis, a genus of Central African treefrogs, includes 51 species that live in tropical forests and savannas. Currently, only two species of Leptopelis are known from the poorly explored Itombwe Plateau in eastern Democratic Republic of the Congo (DRC). Itombwe is renowned among conservationists for its rich and endemic amphibian fauna, including: Xenopus itombwensis, Chrysobatrachus cupreonitens, Laurentophryne parkeri, Hyperolius leleupi and at least three species of Arthroleptis. Evolutionary relationships of Itombwe Leptopelis were examined by sequencing two mitochondrial genes (16S: 557 bp [base pairs], cyt b: 620 bp) and one nuclear gene (RAG1: 761 bp). Results recovered strong support for …


Revealing The Appetite Of The Marine Aquarium Fish Trade: The Volume And Biodiversity Of Fish Imported Into The United States, Andrew L. Rhyne, Michael F. Tlusty, Pamela J. Schofield, Les Kaufman, James A. Morris Jr, Andrew W. Bruckner Jan 2012

Revealing The Appetite Of The Marine Aquarium Fish Trade: The Volume And Biodiversity Of Fish Imported Into The United States, Andrew L. Rhyne, Michael F. Tlusty, Pamela J. Schofield, Les Kaufman, James A. Morris Jr, Andrew W. Bruckner

Arts & Sciences Faculty Publications

The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it. Herein, we discuss the lack of a data system for monitoring the wildlife aquarium trade and analyze problems that arise when trying to monitor the …


A Synthesis Of Plant Invasion Effects On Biodiversity Across Spatial Scales, Kristin I. Powell, Jonathan M. Chase, Tiffany M. Knight Mar 2011

A Synthesis Of Plant Invasion Effects On Biodiversity Across Spatial Scales, Kristin I. Powell, Jonathan M. Chase, Tiffany M. Knight

Biology Faculty Research

PREMISE OF THE STUDY:

Invasive plant species are typically thought to pose a large threat to native biodiversity, and local-scale studies typically confirm this view. However, plant invaders rarely cause regional extirpations or global extinctions, causing some to suggest that invasive species' influence on native biodiversity may not be so dire. We aim to synthesize the seemingly conflicting literature in plant invasion biology by evaluating the effects of invasive plant species across spatial scales.

METHODS:

We first conducted a meta-analysis on the effects of invasive plants on the species richness of invaded communities across a range of spatial extents. We …


Research, Monitoring, Assessment And Development Plan 2010 – 2011, Department Of Fisheries Jan 2011

Research, Monitoring, Assessment And Development Plan 2010 – 2011, Department Of Fisheries

Fisheries Occasional Publications

No abstract provided.


Invasion By Exotic Earthworms Alters Litter- And Soil-Dwelling Oribatid Mites, Jordan L. Burke, John C. Maerz, Joseph Milanovich, Melanie C. Fisk, Kamal J.K. Gandhi Jan 2011

Invasion By Exotic Earthworms Alters Litter- And Soil-Dwelling Oribatid Mites, Jordan L. Burke, John C. Maerz, Joseph Milanovich, Melanie C. Fisk, Kamal J.K. Gandhi

Biology: Faculty Publications and Other Works

Exotic earthworms are drivers of biotic communities in invaded North American forest stands. Here we used ecologically important oribatid mite (Arachnida: Acari) communities, as model organisms to study the responses of litter- and soil-dwelling microarthropod communities to exotic earthworm invasion in a northern temperate forest. Litter- and soil-dwelling mites were sampled in 2008–2009 from forest areas: (1) with no earthworms; (2) those with epigeic and endogeic species, including Lumbricus rubellus Hoffmeister; and (3) those with epigeic, endogeic, and anecic earthworms including L. terrestris L. Species richness and diversity of litter- and soil-dwelling (0–2 cm soil depth) oribatid mites was 1–2 …


Global Patterns And Predictions Of Seafloor Biomass Using Random Forests, Chih-Lin Wei, Gilbert T. Rowe, Elva Escobar-Briones, Antje Boetius, Thomas Soltwedel, M. Julian Caley, Yousria Soliman, Falk Huettmann, Fangyuan Qu, Zishan Yu, C. Roland Pitcher, Richard L. Haedrich, Mary K. Wicksten, Michael A. Rex, Jeffrey G. Baguley, Jyotsna Sharma, Roberto Danovaro, Ian R. Macdonald, Clifton C. Nunnally, Jody W. Deming, Paul Montagna, Mélanie Lévesque, Jan Marcin Weslawski, Maria Wlodarska-Kowalczuk, Baban S. Ingole, Brian J. Bett, David S. M. Billett, Andrew Yool, Bodil A. Bluhm, Katrin Iken, Bhavani E. Narayanaswamy Dec 2010

Global Patterns And Predictions Of Seafloor Biomass Using Random Forests, Chih-Lin Wei, Gilbert T. Rowe, Elva Escobar-Briones, Antje Boetius, Thomas Soltwedel, M. Julian Caley, Yousria Soliman, Falk Huettmann, Fangyuan Qu, Zishan Yu, C. Roland Pitcher, Richard L. Haedrich, Mary K. Wicksten, Michael A. Rex, Jeffrey G. Baguley, Jyotsna Sharma, Roberto Danovaro, Ian R. Macdonald, Clifton C. Nunnally, Jody W. Deming, Paul Montagna, Mélanie Lévesque, Jan Marcin Weslawski, Maria Wlodarska-Kowalczuk, Baban S. Ingole, Brian J. Bett, David S. M. Billett, Andrew Yool, Bodil A. Bluhm, Katrin Iken, Bhavani E. Narayanaswamy

Biology Faculty Publication Series

A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive …


Foundational Checklist Of The Amphibians Of Wise County, Virginia, Sarah R.A. Davidson, David L. Chambers Oct 2010

Foundational Checklist Of The Amphibians Of Wise County, Virginia, Sarah R.A. Davidson, David L. Chambers

Virginia Journal of Science

The Appalachian Mountains are arguably home to the highest degree of amphibian diversity in the world, particularly caudate (salamander) biodiversity. Despite the high degree of amphibian endemism in the Appalachians, several regions remain unsurveyed for amphibian species. In addition to this knowledge gap, we are in the midst of alarming amphibian biodiversity loss. Thus, it is of the utmost importance to bridge this knowledge gap by conducting surveys before some of these amphibian species are lost. We surveyed Wise County (previously unsurveyed county in the Appalachian Mountains with no records existing in the primary literature) over two years to assess …


Negative Plant–Soil Feedback Predicts Tree-Species Relative Abundance In A Tropical Forest, Scott A. Mangan, Stefan A. Schnitzer, Edward A. Herre, Keenan M.L. Mack, Mariana C. Valencia, Evelyn I. Sanchez, James D. Bever Jun 2010

Negative Plant–Soil Feedback Predicts Tree-Species Relative Abundance In A Tropical Forest, Scott A. Mangan, Stefan A. Schnitzer, Edward A. Herre, Keenan M.L. Mack, Mariana C. Valencia, Evelyn I. Sanchez, James D. Bever

Biological Sciences Faculty Research and Publications

The accumulation of species-specific enemies around adults is hypothesized to maintain plant diversity by limiting the recruitment of conspecific seedlings relative to heterospecific seedlings1,2,3,4,5,6. Although previous studies in forested ecosystems have documented patterns consistent with the process of negative feedback7,8,9,10,11,12,13,14,15,16, these studies are unable to address which classes of enemies (for example, pathogens, invertebrates, mammals) exhibit species-specific effects strong enough to generate negative feedback17, and whether …


Seasonal Patterns Of Arthropod Diversity And Abundance On Big Sagebrush, Artemisia Tridentata, Monte P. Sanford, Nancy J. Huntly Apr 2010

Seasonal Patterns Of Arthropod Diversity And Abundance On Big Sagebrush, Artemisia Tridentata, Monte P. Sanford, Nancy J. Huntly

Biology Faculty Publications

The sagebrush biotype is the largest in the western United States. This vast sagebrush community is thought to harbor equally vast and diverse arthropod communities, but these remain little explored. Our objective was to examine the diversity, abundance, and seasonal phenology of arthropod taxa found on the dominant shrub of the sagebrush ecosystem, big sagebrush (Artemisia tridentata). We wanted to improve understanding of this little-studied arthropod assemblage that may play significant roles in the dynamics of sagebrush populations and the sagebrush ecosystem. We sampled free-living and gall-forming arthropods from a stratified random sample of sagebrush plants at the …


From Energy Gradient And Natural Selection To Biodiversity And Stability Of Ecosystems, Bo Deng Jan 2010

From Energy Gradient And Natural Selection To Biodiversity And Stability Of Ecosystems, Bo Deng

Department of Mathematics: Faculty Publications

The purpose of this paper is to incorporate well-established ecological principles into a foodweb model consisting of four trophic levels --- abiotic resources, plants, herbivores, and carnivores. The underlining principles include Kimura's neutral theory of genetic evolution, Liebig's Law of the Minimum for plant growth, Holling's functionals for herbivore foraging and carnivore predation, the One-Life Rule for all organisms, and Lotka-Volterra's model for intraand interspecific competitions. Numerical simulations of the model led to the following statistical findings: (a) particular foodwebs can give contradicting observations on biodiversity and productivity, in particular, all known functional forms -- - positive, negative, sigmoidal, and …


How Our Health Depends On Biodiversity, Eric Chivian M.D., Aaron Bernstein M.D., M.P.H. Jan 2010

How Our Health Depends On Biodiversity, Eric Chivian M.D., Aaron Bernstein M.D., M.P.H.

Ecosystem Disruption & Climate Change

The eminent Harvard biology Professor Edward O.Wilson once said about ants, “We need them to survive, but they don’t need us at all.” The same, in fact, could be said about countless other insects, bacteria, fungi, plankton, plants, and other organisms. This fundamental truth, however, is largely lost to many of us. Rather, we humans often act as if we are totally independent of Nature, as if our driving thousands of other species to extinction and disrupting the life-giving services they provide will have no effect on us whatsoever.

This summary, using concrete examples from our award-winning Oxford University Press …