Old, multi-aged populations of riparian trees provide an opportunity to improve reconstructions of streamflow. Here, ring widths of 394 plains cottonwood (Populus deltoids, ssp. monilifera) trees in the North Unit of Theodore Roosevelt National Park, North Dakota, are used to reconstruct streamflow along the Little Missouri River (LMR), North Dakota, US. Different versions of the cottonwood chronology are developed by (1) age-curve standardization (ACS), using age-stratified samples and a single estimated curve of ring width against estimated ring age, and (2) time-curve standardization (TCS), using a subset of longer ring-width series individually detrended with cubic smoothing splines of width against year. The cottonwood chronologies are combined with the first principal component of four upland conifer chronologies developed by conventional methods to investigate the possible value of riparian tree-ring chronologies for streamflow reconstruction of the LMR. Regression modeling indicates that the statistical signal for flow is stronger in the riparian cottonwood than in the upland chronologies. The flow signal from cottonwood complements rather than repeats the signal from upland conifers and is especially strong in young trees (e.g. 5–35 years). Reconstructions using a combination of cottonwoods and upland conifers are found to explain more than 50% of the variance of LMR flow over a 1935–1990 calibration period and to yield reconstruction of flow to 1658. The low-frequency component of reconstructed flow is sensitive to the choice of standardization method for the cottonwood. In contrast to the TCS version, the ACS reconstruction features persistent low flows in the 19th century. Results demonstrate the value to streamflow reconstruction of riparian cottonwood and suggest that more studies are needed to exploit the low-frequency streamflow signal in densely sampled age-stratified stands of riparian trees.
Potential demographic and genetic effects of a sterilant applied to wild horse mares
Wild horse populations on western ranges can increase rapidly, resulting in the need for the Bureau of Land Management (BLM) to remove animals in order to protect the habitat that horses share with numerous other species. As an alternative to removals, BLM has sought to develop a long-term, perhaps even permanent, contraceptive to aid in reducing population growth rates. With long-term (perhaps even permanent) efficacy of contraception, however, comes increased concern about the genetic health of populations and about the potential for local extirpation. We used simulation modeling to examine the potential demographic and genetic consequences of applying a mare sterilant to wild horse populations. Using the VORTEX software package, we modeled the potential effects of a sterilant on 70 simulated populations having different initial sizes (7 values), growth rates (5 values), and genetic diversity (2 values). For each population, we varied the treatment rate of mares from 0 to 100 percent in increments of 10 percent. For each combination of these treatment levels, we ran 100 stochastic simulations, and we present the results in the form of tables and graphs showing mean population size after 20 years, mean number of removals after 20 years, mean probability of extirpation after 50 years, and mean heterozygosity after 50 years. By choosing one or two combinations of initial population size, population growth rate, and genetic diversity that best represent a herd of interest, a manager can assess the likely effects of a contraceptive program by examining the output tables and graphs representing the selected conditions.
Alien plant invasion in mixed-grass prairie: effects of vegetation type, stochiasticity, and anthropogenic disturbance in two park units
The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of the six most abundant alien species at Theodore Roosevelt National Park had distributions unrelated to disturbance. We recommend that vegetation type be explicitly taken into account when designing monitoring plans for alien species in natural areas.
Dendroclimatic potential of Plains Cottonwood (Populus deltoides Subsp. Monilifera) from the Northern Great Plains, USA
Edmondson, J., J. Friedman, D. Meko, R. Touchan, J. Scott, and A. Edmondson
A new 368-year tree-ring chronology (A.D. 1643–2010) has been developed in western North Dakota using plains cottonwood (Populus deltoids subsp. monilifera) growing on the relatively undisturbed floodplain of the Little Missouri River in the North Unit of Theodore Roosevelt National Park. We document many slow-growing living trees between 150–370 years old that contradict the common understanding that cottonwoods grow fast and die young. In this northern location, cottonwood produces distinct annual rings with dramatic interannual variability that strongly crossdate. The detrended tree-ring chronology is significantly positively correlated with local growing season precipitation and soil moisture conditions (r = 0.69). This time series shows periods of prolonged low radial tree growth during the known droughts of the instrumental record (e.g. 1931–1939 and 1980–1981) and also during prehistory (e.g. 1816–1823 and 1856–1865) when other paleoclimate studies have documented droughts in this region. Tree rings of cottonwood will be a useful tool to help reconstruct climate, streamflow, and the floodplain history of the Little Missouri River and other northern river systems.
Cottonwood tree rings and climate in western North America
Friedman, J.M., J.R. Edmondson, E.R. Griffin, D.M. Meko, M.F. Merigliano, J.A. Scott, M.L. Scott, and R. Touchan
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Parent Publication Title:
45th Annual Fall Meeting of the American Geophysical Union, San Francisco, CA, December 3-7, 2012
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.
Feathers is a collaborative Sage-grouse connectivity study to examine gene flow across the range-wide distribution of greater sage-grouse is being initiated in collaboration with the Natural Resources Conservation Service through the Sage-Grouse Initiative, the Western Association of Fish and Wildlife Agencies, the USDA Forest Service, and the US Geological Survey. The goal of this study is to collect fine-scale genetic data from greater sage-grouse feathers collected at breeding locations (leks) throughout the entire range covering 11 states and 2 provinces. Over 5,000 leks are currently mapped and visited each year for population monitoring.
White-nose syndrome (WNS) is an emerging and devastating disease of hibernating bats in North America. WNS is caused by a cold-growing fungus (Geomyces destructans) that infects the skin of hibernating bats during winter and causes life-threatening alterations in physiology and behavior. WNS has spread rapidly across the eastern United States and Canada since it was first documented in New York in the winter of 2006. This new disease is causing mass mortality and detrimentally affecting most of the 6 species of bats that hibernate in the northeastern United States. Particularly hard-hit are the little brown bat (Myotis lucifugus), northern long-eared bat (Myotis septentrionalis), eastern small-footed bat (Myotis leibii), and federally endangered Indiana bat (Myotis sodalis). Several more species are also now known to be exposed to the fungus in the Midwest and Southeast. The sudden and widespread mortality associated with white-nose syndrome is unprecedented in any of the world’s bats and is a cause for international concern as the fungus and the disease spread farther north, south, and west. Loss of these long-lived insect-eating bats could have substantial adverse effects on agriculture and forestry through loss of natural pest-control services.
Tracking a Deadly Disease
Because WNS is spreading so rapidly, field surveillance data and diagnostic samples must be managed efficiently so that critical information can be communicated quickly among State and Federal land managers, as well as the public. The U.S. Fish and Wildlife Service, which plays a primary role in coordinating the Federal response to WNS, worked with the USGS Fort Collins Science Center’s Web Applications Team to develop the White-nose Syndrome Disease Tracking System. Version 1.0 of this system, released for Beta testing in May 2011, addresses two critical objectives:
enable state-level resource managers to effectively manage WNS field and laboratory data, and
provide customizable map and data reports of surveillance findings. The WNS Disease Tracking System subsequently was demonstrated to resource managers involved in the WNS response, and system users are assisting with in-depth testing. Once resource-management users are all trained (autumn 2011), they will begin populating the system with surveillance data, much of which will be immediately available to the public.
WNS version 1.0 was released into production in November, 2011 and state points-of-contact are currently being trainined. New users are providing ciritical feedback for WNS version 2.0, which is currently being planned with Fish and Wildlife Region 5 and the National White-nose Syndrome Data Management Team.
Key System Components
Disease Tracking: Customizable disease tracking maps and data exports for all U.S. states and counties
Disease Reporting: Tissue sample database management for authorized resource managers as well as a publicly accessible database of disease reporting contacts for all U.S. States and Federal resource management agencies
Diagnostic Labs: Directory of laboratories involved in white-nose syndrome diagnostic analyses
Modeling the dynamic geochemistry of prairie pothole wetlands
Goldhaber, M.B., C.T. Mills, C.A. Stricker, J.W. Labaugh, D. Mushet, and N.H. Euliss
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Parent Publication Title:
3rd USGS Modeling Conference Denver, CO 7-11 June 2010