Evaluation of Genetic, Behavioral and Morphological Distinctness of Greater Sage-grouse in the Bi-State Planning Area
A sage brush habitat. USGS photo.
The goal of this study was to obtain a more comprehensive understanding of the boundaries of this genetically unique population (where the Bi-State population begins) and to examine the genetic structure within the Bi-State, which is needed to help guide effective management decisions. Our genetic data supports the idea that the Bi-State population represents a genetically unique population and identified the Pine Nut Mountains to be the northern boundary of the Bi-State population. We also found three distinct subpopulations (southern Pine Nut Mountains, mid Bi-State, and White Mountains) within the Bi-State that would benefit from conservation and management actions.
Population Genetic Analysis of Black Swift
A picture of a genetic analysis. USGS image.
The purpose of this study is to investigate population genetic structure of Northern Black Swift populations throughout portions of their range in the United States, important information used for conservation prioritization. In addition, this study will document the degree of connectivity among colonies and levels of diversity within them, as well as examining site fidelity of individual birds.
Examining adaptation in Gunnison Sage-grouse
A male Gunnison Sage-grouse strutting. USGS photo.
The satellite populations of the Gunnison Sage-grouse occupy different areas with a diversity of habitat and local environmental characteristics. With limited gene flow between populations and the potential for different selective pressures acting on each population, there is the potential for locally adapted variation. Local adaptation is important to long-term persistence of populations and pertinent to current management efforts. Pressures of climate change and land-use change differ among the populations, and any existing variation adapted to the unique pressures should be maintained within a population. We are using genomic methods to look within each population for evidence of selection correlated with environmental variation. Identifying adaptive variation can contribute to more targeted management efforts and the intentional maintenance of said variation within populations.
Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States
Pardo, L.H., M.E. Fenn, C.L. Goodale, L.H. Geiser, C.T. Driscoll, E.B. Allen, J.S. Baron, et al
Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge.
The objectives of this project were to synthesize current research relating atmospheric N deposition to effects on terrestrial and freshwater ecosystems in the United States, and to estimate associated empirical N critical loads. The receptors considered included freshwater diatoms, mycorrhizal fungi, lichens, bryophytes, herbaceous plants, shrubs, and trees. Ecosystem impacts included:
individual species, population, and community responses.
Biogeochemical responses included increased N mineralization and nitrification (and N availability for plant and microbial uptake), increased gaseous N losses (ammonia volatilization, nitric and nitrous oxide from nitrification and denitrification), and increased N leaching. Individual species, population, and community responses included increased tissue N, physiological and nutrient imbalances, increased growth, altered root : shoot ratios, increased susceptibility to secondary stresses, altered fire regime, shifts in competitive interactions and community composition, changes in species richness and other measures of biodiversity, and increases in invasive species.
The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1–39 kg N ha 1 yr 1, spanning the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, and trees.
The critical load approach is an ecosystem assessment tool with great potential to simplify complex scientific information and communicate effectively with the policy community and the public. This synthesis represents the first comprehensive assessment of empirical critical loads of N for major ecoregions across the United States.
Detritus, trophic dynamics, and biodiversity
Moore, J.C., E.L. Berlow, D.C. Coleman, P.C. de Ruiter, Q. Dong, A. Hastings, N.C. Johnson, K.S. McCann, K. Melville, P.J. Morin, K. Nadelhoffer, A.D. Rosemond, D.M. Post, J.L. Sabo, K.M. Scow, M.J. Vanni, D.H. Wall
Natural flow regime concepts and theories have established the justification for maintaining or restoring the range of natural hydrologic variability so that physiochemical processes, native biodiversity, and the evolutionary potential of aquatic and riparian assemblages can be sustained. A synthesis of recent research advances in hydroecology, coupled with stream classification using hydroecologically relevant indices, has produced the Hydroecological Integrity Assessment Process (HIP). HIP consists of (1) a regional classification of streams into hydrologic stream types based on flow data from long-term gaging-station records for relatively unmodified streams, (2) an identification of stream-type specific indices that address 11 subcomponents of the flow regime, (3) an ability to establish environmental flow standards, (4) an evaluation of hydrologic alteration, and (5) a capacity to conduct alternative analyses. The process starts with the identification of a hydrologic baseline (reference condition) for selected locations, uses flow data from a stream-gage network, and proceeds to classify streams into hydrologic stream types...
Baron, J.S. Contributing Authors: C.D. Allen, E. Fleishman, L. Gunderson, D. McKenzie, L. Meyerson, J. Oropeza, and N. Stephenson
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Preliminary review of adaptation options for climate-sensitive ecosystems and resources - A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research
Covering about 4% of the United States, the 338,000 km2 of protected areas in the National Park System contain representative landscapes of all of the nation’s biomes and ecosystems. The U.S. National Park Service Organic Act established the National Park System in 1916 “to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.” Approximately 270 national park system areas contain significant natural resources. Current National Park Service policy for national resource parks calls for management to preserve fundamental physical and biological processes, as well as individual species, features, and plant animal communities. Parks with managed natural resources range from large intact (or nearly intact) ecosystems with a full complement of native species—including to predators—to those diminished by disturbances such as within-park or surrounding-area legacies of land use, invasive species, pollution, or regional manipulation of resources. The significance of national parks as representatives of naturally functioning ecosystems and refugia for natural processes and biodiversity increases as surrounding landscapes become increasingly altered by human activities.
FORT scientist’s name in NEON: Helping to light the way for understanding ecological change
For many years, USGS Research Ecologist Tom Stohlgren has been at the forefront of developing and implementing ways of collecting, sharing, and relating information on non-native invasive species that plague native ecosystems and challenge public land managers in the United States. In particular, Dr. Stohlgren has focused on developing the capability to rapidly assess changes in biodiversity and identify habitats vulnerable to invasion. He and his team have built ecological forecasting models that combine field data with satellite and other remotely-sensed data, incorporating various data “layers” that include soils, the mix of native and non-native vegetation, climate, and other measures...