Digital Commons Network^™

Fall 2000, Nsu Oceanographic Center

Currents

No abstract provided.

The Global Decline Of Reptiles, Deja’ Vu Amphibians, J. Whitfield Gibbons, David E. Scott, Travis J. Ryan, Kurt A. Buhlmann, Tracey D. Tiuberville, Brian S. Metts, Judith L. Greene, Tony Mills, Yale Leiden, Sean Poppy, Christopher T. Winne

Scholarship and Professional Work - LAS

Reptile species are declining on a global scale. Six significant threats to reptile populations are habitat loss and degradation, introduced invasive species, environmental pollution, disease, unsustainable use, and global climate change.

Toward An Ecosystem Approach To Remediation In The Great Basin, Ted K. Raab

Ted K. Raab

We consider the web of interactions among geologic materials, soils, plants, and animals to ask, "If mining or other extractive energy technologies occur in desert regions, what do we need to know to return the land to productivity?" The Great Basin represents a formidable challenge in this regard, as winters in these cold deserts and seasonal lack of moisture during parts of the year severely constrain the growing season for vegetation. Due to the nature of current or proposed mining activities in this region, we have chosen to concentrate on two potential pollutants: the trace element selenium (Se) and nitrate …

Biodiversity And Ecosystem Functioning: Importance Of Species Evenness In An Old Field, Brian J. Wilsey, Catherine Potvin

Brian J. Wilsey

Changes in land use, habitat fragmentation, nutrient enrichment, and environmental stress often lead to reduced plant diversity in ecosystems. However, it remains controversial whether these reductions in diversity will affect energy flow and nutrient cycling. Diversity has two components: species richness, or the number of plant species in a given area, and species evenness, or how well distributed abundance or biomass is among species within a community. We experimentally varied species evenness and the identity of the dominant plant species in an old field of Quebec to test whether plant productivity would increase with increasing levels of evenness, and whether …

Rhinocyllus Conicus -- Insights To Improve Predictability And Minimize Risk Of Biological Control Of Weeds, Svata M. Louda

Svata M. Louda Publications

A review of information on the release of Rhinocyllus conicus to control of Carduus spp. thistles in North America suggests at least 8 lessons for future biological control efforts. These lessons include the need for: 1) better a priori quantification of the occurrence and ecological effects of the weed; 2) improved incorporation of ecological criteria to supplement the phylogenetic information used to select plants for pre-release testing; 3) increased assessment of plausible direct and indirect ecological interactions when an agent looks promising but feeding tests suggest it is not strictly monophagous, including ecological factors determining host use and limiting population …

Home Ranges And Movements Of Adult Deer On Fort Chaffee, Arkansas, Gregory G. Humphreys, Thomas A. Nelson

Journal of the Arkansas Academy of Science

We radio-tracked 27 white-tailed deer (Odocoileus virginianus) weekly for one year on Fort Chaffee, Arkansas, to investigate their seasonal home ranges and movements between hunted areas and refuges on this military base. This work resulted in2,123 separate radiolocations, of which 85% (1,799) were suitable for use in home range analyses. We used the McPAAL computer package to estimate home range using the Harmonic Mean and minimum convex polygon (MCP) methods. Harmonic mean estimates were based on 95% contour lines. Home range size differed between the sexes and methods. Male home ranges were larger than those of females (t= 3.32, P<0.01; harmonic mean) (t=2.07, P<0.05; MCP). Average home range sizes for males and females based on the harmonic mean method were estimated to be 483 ha and 181 ha, respectively, whereas home range estimates for males and females using the MCP method were 636 ha and 289 ha, respectively. The average home range size for all deer was 259 ha (harmonic mean) and 379 ha (MCP). We found no evidence that females restricted their home ranges during the fawning period. However, females' home ranges expanded during the breeding season, perhaps to find mates. Few deer moved to refuge areas that were off-limits to hunters during the hunting season.

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

This report documents a pack of 22-23 Wolves (Canis lupus) in central Minnesota. This is larger than the largest pack previously observed on the mainland in the midwestern U.s. during 650 wolf pack-years. Because this record-large pack preyed on White-tailed Deer (Odocoileus virginianus), one of the Wolfs smaller prey, it is evidence that pack size and prey size are not tightly related. It also indicates the size that Wolf packs can attain in the area if fully protected from human persecution.

Do Wolves Affect White-Tailed Buck Harvest In Northeastern Minnesota?, L. David Mech, Michael E. Nelson

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

We used simple linear regression to analyze 8-23 years of data on a wolf (Canis lupus) population and human harvest of white-tailed deer (Odocoileus virginianus) bucks in northeastern Minnesota to determine any effects of wolves on buck harvesting. Over the long term, wolves accounted for at least 14-22% inter-year variation in buck harvest in the region, but an unknown amount of variation in hunter effort have obscured any more precise estimate. For part of the area with poorest habitat, we found strong relationships (r² = 0.66-0.84) between annual wolf numbers and buck harvests from 1988 …

Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley

Department of Entomology: Faculty Publications

1. Adult tiger beetles of the genus Cicindela often co-occur within a habitat but larvae do not. Larvae are sedentary and form usually permanent burrows at the site of oviposition where they require 1-3 years for development.

2. To test niche partitioning based on ovipositional preference, the behavior of two sympatric salt marsh tiger beetles, Cicindela circumpicta and C. togata (Coleoptera: Cicindelidae), were examined.

3. In laboratory studies, female C. circumpicta and C. togata distinguished between experimental salinities, with the former preferring 4 parts per thousand (ppt) and the latter preferring 12 ppt. In the field, C. circumpicta larvae were …

The Habitat Utilization Of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) At Buck Island Reef National Monument, St Croix, U.S Virgin Islands, Roy A. Pemberton

Dissertations, Theses, and Masters Projects

No abstract provided.

The Role Of Stress In Determining Community Structure: Effects Of Hypoxia On An Estuarine Epifaunal Community, Alessandra Sagasti

Dissertations, Theses, and Masters Projects

Community models predict the effects of stress on community structure and processes. I tested the Menge and Sutherland 1987 model in an estuarine epifaunal community experiencing low oxygen stress, termed hypoxia. Epifauna, animals living on the surfaces of substrates, are ecologically important in many estuaries where hypoxia occurs, yet little is known about the effects of hypoxia on these communities. Epifauna formed dense communities in the York River, a tributary of the Chesapeake Bay, USA, despite frequent hypoxia. Abundance and species composition was similar in two areas of the river, even though the downstream study area often experienced lower oxygen …

Factors Affecting The Recruitment Of Riparian Vegetation On The Ord And Blackwood Rivers In Western Australia, Neil Pettit

Theses: Doctorates and Masters

This thesis provides baseline information on the ecological processes involved in the recruitment and regeneration of riparian vegetation. As there has been a paucity of basic ecological studies on riparian vegetation in Australia, the project is broad in scope, and gives a general picture of the factors influencing, the regeneration of riparian vegetation and provides a starting point for more detailed work. The project focuses on factors determining recruitment events and the life history traits of particular species in a river in the cool temperate zone of south western Australia (Blackwood River) and on a river in the dry tropics …