Life Sciences Commons^™

Flow Recommendations To Benefit Endangered Fishes In The Colorado And Gunnison Rivers, Charles W. Mcada

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

Continuing Studies Of Water Quality In Farmington Bay And The Great Salt Lake, Utah, Amy M. Marcarelli, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

For the past three years, an Aquatic Ecology Practicum class at Utah State University has conducted research examining the limnology of Farmington Bay. In 2000, our class discovered that Farmington Bay could be classified as hypereutrophic, and had significantly higher levels of chlorophyll and phytoplankton than the Great Salt Lake proper (Marcarelli et al. 2001). In 2001, individual student projects identified high phosphorus loading into Farmington Bay from surrounding sewage treatment plants, brine shrimp biomass five times lower than in the Great Salt Lake, and that the water in the bay lost all oxygen on a windy night in October …

Determining The Factors That Control Respiration And Carbon Use Efficiency In Crop Plants, Jonathan M. Frantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the literature on plant respiration, there are two viewpoints concerning the source of respiratory control: supply (photosynthate availability) or demand (temperature dependent) limitations. While different studies indicate the primary dependency for respiration is either the supply or demand side, the two paradigms cannot both be true. The relative importance of each paradigm may depend on a number of factors including period of time during which respiration is measured, phase of plant development, environmental conditions, and species.

Studies were performed using continuous CO₂ gas-exchange instrumentation to monitor short- and long-term changes in whole canopies of lettuce, tomato, soybean, and …

Pastoralism Under Pressure: Tracking System Change In Southern Ethiopia, D. Layne Coppock, Solomon Desta

Environment and Society Faculty Publications

While economic development has proven elusive in African pastoral systems, change is pervasive. The Kajiado Maasai, for example, have endured declines in terms of per capita livestock holdings and other aspects of human welfare over the past 50 years. Activity diversification has occurred in Maasailand as the population copes with pressure from human population growth. We surveyed up to 317 Borana households during the late 1990s to see if similar patterns occurred in southern Ethiopia. Once viewed as an example of sustainable pastoralism, the Borana system now confronts numerous challenges. Decline in per capita cattle holdings has spurred household-level diversification …

For Pastoralists The Risk May Be In The Drinking Water: The Case Of Kargi, N. Kenya, D. Layne Coppock, William A. Shivoga

Environment and Society Faculty Publications

Inadequate quantity of water is a common problem for pastoral people in East Africa. For the Rendille community of Kargi in northern Kenya, however, water quality has also been identified as a critical issue. Residents report that water-borne diseases commonly affect human health in dry seasons, and livestock may die soon after drinking water from some of the older, deep wells. We collected water samples from four key wells and one earthen dam to analyze physiochemical and bacteriological quality. Preliminary results indicated that the centrally located, oldest wells tested far below technical quality guidelines in several respects. Especially notable were …

Modeling Habitat Quality For American Martens In Western Newfoundland, Canada, William A. Adair

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The "Den Mother" marten habitat quality models were created to provide insight into American marten habitat selection behavior and to promote the recovery of the Newfoundland marten (Martes americana atrata) population. Although these objectives are typical of most wildlife habitat modeling projects, the marten's idiosyncratic habitat ecology and apparently intractable conflicts associated with timber harvesting motivated a unique, process-oriented approach to appraising landscapes. The Den Mother models used optimal decision-making principles to synthesize critical resources (den sites and foraging opportunities) and constraints (adverse thermal situations and exposure to predations) into a single hierarchical framework. The resulting spatially explicit, …

Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds.

I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected …

Winter Ecology Of Kokanee: Implications For Salmon Management, G. B. Steinhart, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We sampled various limnological parameters and measured growth and diet of age-0 kokanee Oncorhynchus nerka (lacustrine sockeye salmon) during two winters in a high-mountain lake of the Sawtooth Valley, Idaho. Although winter has been recognized as an important period for many warmwater fishes and for stream-dwelling salmonids, winter limitations have only recently been studied for coolwater and coldwater species. Ice and snow cover in winter limited light penetration. As a result, chlorophyll-a and zooplankton density were lower in ice-covered periods than during ice-free periods. The weight of stomach contents was often below a maintenance ration, yet the incidence of empty …