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Ecology and Evolutionary Biology

2007

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Articles 91 - 101 of 101

Full-Text Articles in Physical Sciences and Mathematics

Feeding Ecology Of Asiatic Wild Ass Equus Hemionus, Jochen Lengger, Frieda Tataruch, Christian Walzer Jan 2007

Feeding Ecology Of Asiatic Wild Ass Equus Hemionus, Jochen Lengger, Frieda Tataruch, Christian Walzer

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

The Mongolian wild ass or khulan (Equus hemionus) is a potential competitor for forage to reintroduced Przewalski’s horses. To evaluate the major foraging plants of khulan we chose the alkane method that was first described by Mayes in 1984. Different plant species contain varying amounts and proportions of n-alkanes. This fact allows the determination of diet composition by comparing the plant alkane to the fecal alkane pattern. The major advantage is that the method is non-invasive and has been shown to be a reliable method in captive trials. Fecal and plant samples were collected simultaneously and preserved by …

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Social Networks In Wild Asses: Comparing Patterns And Processes Among Populations, Daniel I. Rubenstein, Siva Sundaresan, Ilya Fischhoff, David Saltz Jan 2007

Social Networks In Wild Asses: Comparing Patterns And Processes Among Populations, Daniel I. Rubenstein, Siva Sundaresan, Ilya Fischhoff, David Saltz

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

Asiatic wild asses inhabit some of the most arid environments in the world. All live in fissionfusion societies, but demography varies and the deserts in which they live often differ in subtle ways. Characterizing details of social structure of wild ass populations has been a challenge and has made it difficult to determine causes and consequences of any differences that might exist. We use network theory to compare the social structures of two populations of Asiatic asses/ onagers inhabiting the Negev desert, Israel and khur of the Little Rann of Kuch, India and show that populations differ in important structural …

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Numbers, Distribution And Social Structure Of Kiang (Equus Kiang Moorcroft 1841) Population In The Southwestern Part Of Tibet, China, Natalia V. Paklina, Chris Van Orden Jan 2007

Numbers, Distribution And Social Structure Of Kiang (Equus Kiang Moorcroft 1841) Population In The Southwestern Part Of Tibet, China, Natalia V. Paklina, Chris Van Orden

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

In September - October 1998 we made an extensive survey in southwest Tibet to study numbers, distribution and social structure of the kiang population in this remote part of its range. Kiangs were sighted between 29º 40’ and 32º 50’ N, and 81º- 86º E. They preferred broad flat valleys with lakes at an altitude from 4,000 up to 5,000 m. Small kiang groups and solitary animals were sighted in Transhimalaya. There were no kiangs in Tsangpo (Brahmaputra) River valley, in the sand desert near Ali and in the Clay Mountains near Tsada. Seven old kiang corpses were found along …

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Introduction To The Integrated Guidance Concept, Center For Coastal Resources Management, Virginia Institute Of Marine Science Jan 2007

Introduction To The Integrated Guidance Concept, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay.

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Response Of Eelgrass Zostera Marina To Co2 Enrichment: Possible Impacts Of Climate Change And Potential For Remediation Of Coastal Habitats, Sherry L. Palacios, Richard C. Zimmerman Jan 2007

Response Of Eelgrass Zostera Marina To Co2 Enrichment: Possible Impacts Of Climate Change And Potential For Remediation Of Coastal Habitats, Sherry L. Palacios, Richard C. Zimmerman

OES Faculty Publications

Projected increases in dissolved aqueous concentrations of carbon dioxide [CO2(aq)] may have significant impacts on photosynthesis Of CO2-limited organisms such as seagrasses. Short-term CO2(aq) enrichment increases photosynthetic rates and reduces light requirements for growth and survival of individual eelgrass Zostera marina L. shoots growing in the laboratory under artificial light regimes for at least 45 d. This study examined the effects of long-term CO2(aq) enrichment on the performance of eelgrass growing under natural light-replete (33% surface irradiance) and light-limited (5% surface irradiance) conditions for a period of 1 yr. Eelgrass shoots were grown at …

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Termite Resource Partitioning Related To Log Diameter, Deborah A. Waller Jan 2007

Termite Resource Partitioning Related To Log Diameter, Deborah A. Waller

Biological Sciences Faculty Publications

The termites Reticuliterines virginicus and R. flavipes are sympatric in forests along the eastern United States from Florida to Maryland. These congeners construct subterranean nests, forage on surface and buried wood, and appear to have very similar ecological requirements. In the present study, I examined host-wood selection by these species in a coastal forest over two years. Logs inhabited by R. virginicus had significantly greater diameters than those used by R. flavipes. It is not known whether this pattern resulted from species-specific differences in preference for host size or competition for preferred logs. Host-wood temperature did not differ for …

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Chumming On The Chesapeake Bay And Complexity Theory: Why The Precautionary Principle, Not Cost-Benefit Analysis, Makes More Sense As A Regulatory Approach, Hope M. Babcock Jan 2007

Chumming On The Chesapeake Bay And Complexity Theory: Why The Precautionary Principle, Not Cost-Benefit Analysis, Makes More Sense As A Regulatory Approach, Hope M. Babcock

Georgetown Law Faculty Publications and Other Works

Estuaries like the Chesapeake Bay ("Bay") and Puget Sound are in grave trouble. They each suffer from poor water quality, loss of habitat, and declining biodiversity, and efforts to restore their health are straining both public and private resources. While accomplishments are often recorded in the fight against these ills, it is clear these accomplishments "are not yet equal to the scale of the problems." The focus of this article is on the nation's largest estuary, the Bay. Despite the investment of billions of dollars to improve water quality, the Bay continues to suffer from severe environmental degradation that impairs …

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Administering The Clean Water Act: Do Regulators Have "Bigger Fish To Fry" When It Comes To Addressing The Practice Of Chumming On The Chesapeake Bay?, Hope M. Babcock Jan 2007

Administering The Clean Water Act: Do Regulators Have "Bigger Fish To Fry" When It Comes To Addressing The Practice Of Chumming On The Chesapeake Bay?, Hope M. Babcock

Georgetown Law Faculty Publications and Other Works

The Chesapeake Bay is one of the country's most productive estuaries. However, for decades the health of the Bay has been declining due in large part to nutrification. Excessive nutrients encourage algal blooms, which lower dissolved oxygen and increase turbidity in the Bay's waters. More than 40% of the Bay's main stern is now dead largely as a result of this problem. The practice of chumming, the discarding of baitfish, usually menhaden, over the sides of fishing boats to attract game fish like striped bass, is contributing to the Bay's nutrification problem because the decomposing chum raises the waters biological …

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Past, Present, And Future Old Growth In Frequent-Fire Conifer Forests Of The Western United States, Scott R. Abella, W. Wallace Covington, Peter Z. Fule, Leigh B. Lentile, Andrew J. Sanchez Meador, Penelope Morgan Jan 2007

Past, Present, And Future Old Growth In Frequent-Fire Conifer Forests Of The Western United States, Scott R. Abella, W. Wallace Covington, Peter Z. Fule, Leigh B. Lentile, Andrew J. Sanchez Meador, Penelope Morgan

Public Policy and Leadership Faculty Publications

Old growth in the frequent-fire conifer forests of the western United States, such as those containing ponderosa pine (Pinus ponderosa), Jeffrey pine (P. jeffreyi), giant sequoia (Sequioa giganteum) and other species, has undergone major changes since Euro-American settlement. Understanding past changes and anticipating future changes under different potential management scenarios are fundamental to developing ecologically based fuel reduction or ecological restoration treatments. Some of the many changes that have occurred in these forests include shifts from historically frequent surface fire to no fire or to stand-replacing fire regimes, increases in tree density, increased abundance of fire-intolerant trees, decreases in understory …

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Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan Jan 2007

Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan

Biological Sciences Theses & Dissertations

The habitats at the VCR LTER that were the focus of the current study are the Hog Island and Parramore Island 'pimples', small, rounded dunes forming along main dune ridges of the barrier islands. There are distinct plant assemblage zones found on pimples, although most of these dunes are 10–20 m in diameter. Hypotheses of the study were that fresh water availability was a main determinant of differences between assemblages and that pimple size and location would influence diversity and assemblage structure. Research goals were (1) to describe the plant assemblages on pimples, (2) to relate edaphic and geomorphological factors …

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In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant Dec 2006

In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant

Donald J. Kochan

Significant research has been conducted into the utilization of geothermal resources as a ‘green’ energy source. However, minimal research has been conducted into geothermal resource utilization and depletion impacts on thermophile biodiversity. Thermophiles are organisms which have adapted over millions of year to extreme temperature and chemical compositions and exist in hot springs and other geothermal resources. Their ability to withstand high temperatures makes them invaluable to scientific and medical research. Current federal and California case law classify geothermal resources as a mineral, not a water resource. Acquisition of rights to develop a geothermal resource owned or reserved by the …

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