Examining Current Subspecies Delineations in White-tailed Ptarmigan Using Genomic Data
A White-tailed Ptarmigan on Mt. Evans, Colorado. Photo by Cameron Aldridge, USGS.
The delineation of populations that are evolutionarily and demographically distinct is an important step in the development of species-specific management plans. Such knowledge is necessary for learning how conservation threats vary across a species’ range, for devising strategies to increase population growth rates, and for providing legal protection at the intraspecific level. It is also essential for conserving long-term evolutionary resilience, given that the genetic diversity that has evolved in response to spatial variation in environmental conditions could provide the raw ingredients necessary to fuel future adaptive evolution. We are using genomic data to delineate distinct evolutionary units across the range of the white-tailed ptarmigan. This information will inform management strategies for this alpine species, which may be vulnerable to climate change.
Unsupported inferences of high-severity fire in historical dry forests of the western United States: response to Williams and Baker
Fulé, P.Z., T.W. Swetnam, P.M. Brown, D.A. Falk, D.L. Peterson, C.D. Allen, G.H. Aplet, M.A. Battaglia, D. Binkley, C. Farris, R.E. Keane, E.Q. Margolis, H. Grissino-Mayer, C. Miller, C. Hull Sieg, C. Skinner, S.L. Stephens, and A. Taylor
Reconstructions of dry western US forests in the late 19th century in Arizona, Colorado and Oregon based on General Land Office records were used by Williams & Baker (2012; Global Ecology and Biogeography, 21, 1042–1052; hereafter W&B) to infer past fire regimes with substantial moderate and high-severity burning. The authors concluded that present-day large, high-severity fires are not distinguishable from historical patterns. We present evidence of important errors in their study. First, the use of tree size distributions to reconstruct past fire severity and extent is not supported by empirical age–size relationships nor by studies that directly quantified disturbance history in these forests. Second, the fire severity classification of W&B is qualitatively different from most modern classification schemes, and is based on different types of data, leading to an inappropriate comparison. Third, we note that while W&B asserted ‘surprising’ heterogeneity in their reconstructions of stand density and species composition, their data are not substantially different from many previous studies which reached very different conclusions about subsequent forest and fire behaviour changes. Contrary to the conclusions of W&B, the preponderance of scientific evidence indicates that conservation of dry forest ecosystems in the western United States and their ecological, social and economic value is not consistent with a present-day disturbance regime of large, high-severity fires, especially under changing climate.
Influence of nonnative and native ungulate biomass and seasonal precipitation on vegetation production in a great basin ecosystem
Zeigenfuss, L.C., K.A. Schoenecker, J.I. Ransom, D.A. Ignizio and T. Mask
The negative effects of equid grazers in semiarid ecosystems of the American West have been considered disproportionate to the influence of native ungulates in these systems because of equids’ large body size, hoof shape, and short history on the landscape relative to native ungulates. Tools that can analyze the degree of influence of various ungulate herbivores in an ecosystem and separate effects of ungulates from effects of other variables (climate, anthropomorphic disturbances) can be useful to managers in determining the location of nonnative herbivore impacts and assessing the effect of management actions targeted at different ungulate populations. We used remotely sensed data to determine the influence of native and nonnative ungulates and climate on vegetation productivity at wildlife refuges in Oregon and Nevada. Our findings indicate that ungulate biomass density, particularly equid biomass density, and precipitation in winter and spring had the greatest influence on normalized difference vegetation index (NDVI) values. Our results concur with those of other researchers, who found that drought exacerbated the impacts of ungulate herbivores in arid systems.
Dam removal and anadromous salmonid (Oncorhynchus spp.) conservation in California
Quiñones, R.M., T.E. Grantham, B.N. Harvey, J.D. Kiernan, M. Klasson, A.P. Wintzer, and P.B. Moyle
Dam removal is often proposed for restoration of anadromous salmonid populations, which are in serious decline in California. However, the benefits of dam removal vary due to differences in affected populations and potential for environmental impacts. Here, we develop an assessment method to examine the relationship between dam removal and salmonid conservation, focusing on dams that act as complete migration barriers. Specifically, we (1) review the effects of dams on anadromous salmonids, (2) describe factors specific to dam removal in California, (3) propose a method to evaluate dam removal effects on salmonids, (4) apply this method to evaluate 24 dams, and (5) discuss potential effects of removing four dams on the Klamath River. Our flexible rating system can rapidly assess the likely effects of dam removal, as a first step in the prioritization of multiple dam removals. We rated eight dams proposed for removal and compared them with another 16 dams, which are not candidates for removal. Twelve of the 24 dams evaluated had scores that indicated at least a moderate benefit to salmonids following removal. In particular, scores indicated that removal of the four dams on the Klamath River is warranted for salmonid conservation. Ultimately, all dams will be abandoned, removed, or rebuilt even if the timespan is hundreds of years. Thus, periodic evaluation of the environmental benefits of dam removal is needed using criteria such as those presented in this paper.
Environmental contaminants and biomarker responses in fish from the Columbia River and its tributaries: Spatial and temporal trends
The Greater Sage-Grouse, has been observed, hunted, and counted for decades. The sagebrush biome, home to the Greater Sage-Grouse, includes sagebrush-steppe and Great Basin sagebrush communities, interspersed with grasslands, salt flats, badlands, mountain ranges, springs, intermittent creeks and washes, and major river systems, and is one of the most widespread and enigmatic components of Western U.S. landscapes. Over time, habitat conversion, degradation, and fragmentation have accumulated across the entire range such that local conditions as well as habitat distributions at local and regional scales are negatively affecting the long-term persistence of this species. Historic patterns of human use and settlement of the sagebrush ecosystem have contributed to the current condition and status of sage-grouse populations. The accumulation of habitat loss, persistent habitat degradation, and fragmentation by industry and urban infrastructure, as indicated by U.S. Fish and Wildlife Service (USFWS) findings, presents a significant challenge for conservation of this species and sustainable management of the sagebrush ecosystem. Because of the wide variations in natural and human history across these landscapes, no single prescription for management of sagebrush ecosystems (including sage-grouse habitats) will suffice to guide the collective efforts of public and private entities to conserve the species and its habitat.
This report documents and summarizes several decades of work on sage-grouse populations, sagebrush as habitat, and sagebrush community and ecosystem functions based on the recent assessment and findings of the USFWS under consideration of the Endangered Species Act. As reflected here, some of these topics receive a greater depth of discussion because of the perceived importance of the issue for sagebrush ecosystems and sage-grouse populations. Drawing connections between the direct effects on sagebrush ecosystems and the effect of ecosystem condition on habitat condition, and finally the connection between habitat quality and sage-grouse population dynamics remains an important goal for science, management, and conservation. This effort is necessary, despite the perception that these complicated, indirect relations are difficult to characterize and manage, and the many advances in understanding and application developed toward this end have been documented here to help inform regional planning and policy decisions.
The state of amphibians in the United States
Muths, E., M.J. Adams, E.H.C. Grant, D. Miller, P.S. Corn, and L.C. Ball
More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and commerce. This fact sheet provides a snapshot of the state of the amphibians and introduces examples to illustrate the range of issues in the United States.
ASPN is a Web-based decision tool that assists natural resource managers and planners in identifying and prioritizing social and economic planning issues, and provides guidance on appropriate social and economic methods to address their identified issues.
ASPN covers the breadth of issues facing natural resource management agencies so it is widely applicable for various resources, plans, and projects.
ASPN also realistically accounts for budget and planning time constraints by providing estimated costs and time lengths needed for each of the possible social and economic methods.
ASPN is a valuable starting point for natural resource managers and planners to start working with their agencies’ social and economic specialists. Natural resource management actions have social and economic effects that often require appropriate analyses. Additionally, in the United States, Federal agencies are legally mandated to follow guidance under the National Environmental Policy Act (NEPA), which requires addressing social and economic effects for actions that may cause biophysical impacts. Most natural resource managers and planners lack training in understanding the full range of potential social and economic effects of a management decision as well as an understanding of the variety of methods and analyses available to address these effects. Thus, ASPN provides a common framework which provides consistency within and across natural resource management agencies to assist in identification of pertinent social and economic issues while also allowing the social and economic analyses to be tailored to best meet the needs of the specific plan or project.
ASPN can be used throughout a planning process or be used as a tool to identify potential issues that may be applicable to future management actions. ASPN is useful during the pre-scoping phase as a tool to start thinking about potential social and economic issues as well as to identify potential stakeholders who may be affected. Thinking about this early in the planning process can help with outreach efforts and with understanding the cost and time needed to address the potential social and economic effects. One can use ASPN during the scoping and post-scoping phases as a way to obtain guidance on how to address issues that stakeholders identified. ASPN can also be used as a monitoring tool to identify whether new social and economic issues arise after a management action occurs.
ASPN is developed through a collaborative research effort between the USGS Fort Collins Science Center’s (FORT) Social and Economic Analysis (SEA) Branch and the U.S. Forest Service, the National Park Service, the Bureau of Land Management, and the U.S. Fish and Wildlife Service. ASPN’s technical development is led by the USGS FORT’s Information Science Branch. An updated release, which will extend ASPN’s functionality and incorporate feature improvements identified in ongoing usability testing, is currently in the planning stages.