National Science Foundation Awards Grants for Environmental Biology
Researchers Seek Basic Knowledge to Support Conservation and Restoration
Cheryl Dybas (NSF PR 94-51)
Around the world, animals and plants are becoming extinct at unprecedented rates. As human civilization encroaches on nature, entire ecosystems are threatened. Determining the fate of life on Earth has challenged biologists seeking to understand connectedness, continuity, and complexity in ecosystems.
To advance knowledge of ecosystems and species under pressure, the National Science Foundation (NSF) has awarded 14 grants in its conservation biology and restoration ecology program in the division of environmental biology.
Threats to biological diversity occur across geographic regions, at all levels of organization, and on scales ranging from the microscopic to the oceanic. NSF grantees will work not only in the United States, but also at sea and on land in other countries.
Support for this fifth year of awards totaled approximately $2 million. General areas of research include assessments of the diversity contained within gene pools of different species, the fate over generations of individual gene variants within species, the effects of species diversity within ecosystems, and hormonal and behavioral factors affecting animal reproduction.
Descriptions of some of the conservation biology and restoration biology awards follow:
Mammal Biodiversity of the Olympic Peninsula
Research by Mark V. Lomolino of the University of Oklahoma will provide important insights on two questions central to efforts to conserve biodiversity: the effects of fragmentation and the potential benefits of so-called wildlife corridors. Lomolino's work involves determining the effects of fragmentation on mammal biodiversity in old-growth forests of the Olympic Peninsula. Spatial analysis techniques will be used to investigate how the ecological structure of old-growth forest animal communities reflects differences among species, forest fragments, and surrounding landscapes. Subsequently, these patterns will be used to assess the importance of corridors to the biodiversity of old-growth forest mammals, and to find out which landscape features favor immigrations of forest mammals.
Field studies will involve surveys conducted in nine continuous forest sites, 30 fragments of old-growth forest, and 10 locations along corridors and within clearcuts. Information on distribution patterns in the fragmented landscape of the Olympic National Forest will facilitate efforts to manage these forests for mammals and species dependent on these mammals for food, such as spotted owls. This research will also provide general insights into the effects of forest fragmentation by serving as a case study that documents the effects of fragmentation and assesses the influence of ecological processes influencing biodiversity.
Role of Fire in Southwestern Ecosystems
Determining changes in a southwestern ponderosa pine/bunchgrass ecosystem that have occurred since the time of Euro-American settlement is the goal of researcher W.W. Covington of Northern Arizona University. Covington believes these changes may be related to natural fires. Trees, shrubs, herbaceous vegetation, coarse woody debris, and the forest floor will be mapped on plots in two southwestern U.S. study areas. These data will be used to estimate post-settlement changes in aboveground biomass, decomposition, nutrient cycling characteristics, and old-growth tree physiology and susceptibility to insect attacks.
Experiments involve complete restoration of the forest to a pre-settlement state (thinning post-settlement trees, removing forest floor, and burning at natural intervals), and partial restoration (thinning post-settlement trees). Previous research has shown that introducing fire without first removing forest floor materials results in death of overstory trees and damage to belowground systems," says Covington. New research will further our understanding of the role of fire in ecosystem restoration in southwestern forest systems, and enhance our knowledge of the role of natural disturbances in forest ecosystems.
Butterfly Migration in Costa Rica
Migration is a widely recognized but poorly understood phenomenon in the tropics. Species that migrate need special consideration in conservation plans because they depend on at least two seasonal habitats. They rely on resources at stop-over sites along their migration paths - for example, the east-west migration of butterflies over the mountains near Monteverde, Costa Rica. A surprisingly large fraction, approximately 80% (260 species), of Pacific slope and lowland animals in Costa Rica move seasonally to the Atlantic side.
Robert D. Stevenson of the University of Massachusetts at Boston will quantify the magnitude, direction, and temporal components of these migrants of the Monteverde region. Changes in population levels will be studied along the entire migration route. A comparison of life-history traits will be used to rank habitat specialization and migration capability of these species. Comparisons will also be made between migrants and permanent residents of the inland dry forest to examine their relative sensitivities to habitat fragmentation. Says Stevenson, "These studies will advance the conservation of tropical invertebrates and increase our ability to identify the unique resource needs of migrant species."
Are Amphibian Declines Related to Immune Function?
Recent reports of world-wide declines and extinctions of amphibian populations have raised questions about the relationship between environmental change and the demise of certain amphibian species. If these species are being harmed by man-induced changes, amphibians may prove to be excellent indicators of ecosystem stress. But the causes of amphibian population declines have not been conclusively demonstrated. If a change in one factor, or changes in several factors, occur in the amphibian's environment, the changes may directly or indirectly suppress function of amphibian immune systems.
"This depression of immune function, coupled with the additional effects of seasonally-associated cold body temperatures, leads to increased susceptibility to disease. In turn, this susceptibility often results in death of the individual and ultimate demise of the population," say scientists like Cynthia Carey of the University of Colorado. Carey will evaluate the role of changes thought to be causing suppression of immune function and disease in threatened amphibian populations.
Population Genetics of Tropical Forest Trees
Kamaljit S. Bawa of the University of Massachusetts at Boston will examine the effects of deforestation and forest fragmentation on genetic diversity and gene dispersal patterns in the tropical lowland rain forests of Costa Rica. Specific goals are to measure the amount of genetic differentiation in tropical tree populations over relatively small spatial scales, and ascertain whether fragmented populations possess the same level of genetic diversity as those of a larger forest of equal size.
Genetic variation will be studied using a variety of genetic markers. Experiments developed by Bawa for research on tropical tree species will be used to estimate levels of gene flow and inbreeding. Says Bawa, "Deforestation and forest fragmentation are ubiquitous in the tropics and are presumed to result in loss of biodiversity, including genetic diversity within species. However, there are no estimates of this loss of genetic diversity within species of tropical forest trees. One reason for this lack of knowledge is that the population genetics of tropical trees has been poorly understood in the past."
The National Science Foundation is an independent agency of the federal government established in 1950 to promote and advance scientific progress in the United States. NSF accomplishes its mission primarily by competitively awarding grants to educational institutions for research and education in the sciences, mathematics, and engineering.
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