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Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of...

Communities of submersed aquatic vegetation (SAV) provide critical habitat for wintering waterfowl and many commercially important fish species. Submersed aquatic vegetation also helps minimize storm damage by reducing wave action and stabilizing sediments, and they improve water quality by sequestering nutrients and contaminants (Zieman and Zieman 1989)....

Extirpated in most of the Great Lakes, the shortjaw cisco, Coregonus zenithicus, is currently found in Lakes Superior and Nipigon in addition to at least 22 Canadian lakes. The species exhibits morphological and genetic variability throughout its range and may consist of more than one distinct taxon. However, a common...

No abstract available....

We cultured 126 Pasteurella multocida isolates, 92 from water and 34 from sediment samples collected from wetlands in the Pacific and Central flyways of the United States between 1996 and 1999. Most (121) of the isolates were P. multocida serotype 1, but serotypes 3, 3/4, 10, and 11 were also...

As a result of recent fire history and decades of even-aged forest management, many coniferous forests in western Oregon are composed of young (20-50 yrs), densely stocked Douglas-fir stands. Often these stands are structurally simple - a single canopy layer with one or two overstory tree species - and have a relatively...

A stepwise regression tree (SRT) algorithm was developed for approximating complex nonlinear relationships. Based on the regression tree of Breiman et al . (BRT) and a stepwise linear regression (SLR) method, this algorithm represents an improvement over SLR in that it can approximate nonlinear relationships and over BRT in that...

Landslides in the hilly terrain along the Kansas and Missouri rivers in northeastern Kansas have caused millions of dollars in property damage during the last decade. To address this problem, a statistical method called multiple logistic regression has been used to create a landslide-hazard map for Atchison, Kansas, and surrounding...

The role of wildland fire in the winter habitat use of caribou (Rangifer tarandus) has long been debated. Fire has been viewed as detrimental to caribou because it destroys the slow-growing climax forage lichens that caribou utilize in winter. Other researchers argued that caribou were not reliant on lichens and...

Conditional distribution coefficients (KDOM‘) for Hg(II) binding to seven dissolved organic matter (DOM) isolates were measured at environmentally relevant ratios of Hg(II) to DOM. The results show that KDOM‘ values for different types of samples (humic acids, fulvic acids, hydrophobic acids) isolated from diverse aquatic environments were all...

We compared abundance and length structure estimates of cutthroat trout (Oncorhynchus clarki) and brown trout (Salmo trutta) of 15 cm total length or greater obtained by snorkeling in stream pools with estimates obtained by depletion electrofishing. We sampled 12 pools in each of two streams formed by large springs in the Salt River Valley of western Wyoming. Snorkeling counts provided a relatively accurate index of depletion electrofishing estimates of abundance of cutthroat trout, but not brown trout....

Hydrologic processes control much of the export of organic matter and nutrients from the land surface. It is the variability of these hydrologic processes that produces variable patterns of nutrient transport in both space and time. In this paper, we explore how hydrologic “connectivity” potentially affects nutrient transport. Hydrologic connectivity...

Mechanisms underlying catchment export of nitrogen (N) during seasonal transitions (i.e., winter to spring and summer to autumn) were investigated in high-elevation catchments of the Sierra Nevada using stable isotopes of nitrate and water, intensive monitoring of stream chemistry and detailed catchment N-budgets. We had four objectives: (1) determine the...

[1] We present a new crustal section across northwest China based on a seismic refraction profile and geologic mapping. The 1100‐km‐long section crosses the southern margin of the Chinese Altai Mountains, Junggar Accretional Belt and eastern Junggar basin, easternmost Tianshan Mountains, and easternmost Tarim basin. The crustal...

Invasions of boll weevil (Anthonomus grandis) into the United States and sea lamprey (Petromyzon marinus) into the Great Lakes were similar in many ways. Important species (American cotton, Gossypium hirsutum, and lake trout, Salvelinus namaycush) and the industries they supported were negatively affected. Initial control efforts were unsuccessful until pesticides...

Both frequency and intensity of disturbances in many ecosystems have been greatly enhanced by increasing human activities. As a consequence, the short-lived plant species including many exotics might have been dramatically increased in term of both richness and abundance on our planet while many long-lived species might have been lost....

This paper aims at determining how different floristic elements (e.g. cosmopolitan, tropical, and temperate) change with latitude and major climate factors, and how latitude affects the floristic relationships between East Asia and the other parts of the world. The large-scale patterns of phytogeography in East Asia are strongly related to...

There are many inconsistencies in early reports describing the relationships between plant abundance and other biotic (e.g., seed size) or abiotic variables (e.g., precipitation). It has been difficult to generalize such relationships when abundance is measured differently (e.g., density, biomass, cover). This article suggests using abundance in two broad categories:...

Species-abundance relationship is one of the most fundamental aspects of community ecology. Since Motomura first developed the geometric series model to describe the feature of community structure, ecologists have developed many other models to fit the species-abundance data in communities. These models can be classified into empirical and theoretical ones,...

Mallard (Anas platyrhynchos) may winter in northern areas if they have access to adequate food and open water. We compared individual body size (indexed by first principal component scores from three morphometric measurements) and body condition (body mass adjusted for body size) of male Mallard wintering in North Dakota,...

Grassland bird populations are declining. Invasive plant species may be contributing to these declines by altering habitat quality. However, the effects of invasive plants on grassland birds are largely unknown. Leafy spurge (Euphorbia esula) is an exotic, invasive weed in the northern Great Plains. We examined the effects of leafy spurge infestation on densities of breeding birds, nest-site selection, and nest success in grasslands on the Sheyenne...

Diversity-biomass relationships are frequently reported to be hump-shaped over space at a given time. However, it is not yet clear how diversity and biomass change simultaneously and how they are related to each other over time (e.g. in succession) at one locality. This study develops a temporal model based on...

The implementation of a sterile-male-release technique from 1991 through 1999 and evaluation of its effectiveness in the Great Lakes sea lamprey (Petromyzon marinus) management program is reviewed. Male sea lampreys were injected with the chemosterilant bisazir (P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide) using a robotic device. Quality assurance testing indicated the device delivered a...

Seasonally operated barriers in rivers are used by the Great Lakes Fishery Commission to block adult sea lamprey (Petromyzon marinus) migrations, yet pass other fish during some part of the year. Knowledge of the overlap of spawning migrations of sea lampreys and other fish species are vital for the efficient...

An updated oligochaete species list for the Great Lakes region is provided. The list was developed through the reexamination of the taxa reported in a previous report in 1980, addition of new taxa or records collected from the region since 1980, and an update of taxonomy commensurate with systematic and...