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.
Response of mountain plovers to plague-driven dynamics of black-tailed prairie dog colonies
Landscape Conservation Cooperatives (LCCs) are applied conservation science partnerships focused on a defined geographic area that informs on-the-ground strategic conservation efforts at landscape scales. LCC partners include DOI agencies, other federal agencies, states, tribes, non-governmental organizations, universities, and others. The U.S. Fish and Wildlife Service is working with partners to develop the Great Plains Landscape Conservation Cooperative (GPLCC) that encompasses parts of eight states: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Some of the most imperiled habitats in the U.S are found in this area (short-grass and mixed-grass prairies; playa wetlands; riparian streams; prairie rivers; cross-timbers; and savannahs, shrublands, and sand dune systems), along with a number of imperiled species. The Fort Collins Science Center, in collaboration with the USGS Colorado Water Science Center, is providing expertise on playa lakes, landscape ecology, and surface- and groundwater hydrology to help inform management actions for greater impact on priority habitats and species.
Climate models predict increased warming, throughout the LCC area, and for some areas of the geography, greater precipitation. Maximum and minimum temperatures rise in both scenarios. Minimum temperature increases are greatest, indicating increased nighttime warming. Models show both increases and decreases in precipitation over the region and the seasons, although the overall trend is anticipated to be slightly wetter in the Great Plains region. The snow season in the Great Plains is projected to end earlier in the spring, reflecting greater warming in winter and spring. Regional change in climate variability and extreme events may affect various aspects of Great Plains ecosystems.
· Changes in winter moisture may impact cool season invasive plants, the extent of sagebrush and other woody perennials on the range, shallow aquifer recharge, stream flow timing, and forage availability and quality.
· Warmer winters may impact the incidence of pest outbreaks, soil organic matter, plant community composition, and the invasion of exotic plants. For example, leafy spurge and Japanese brome may move further south.
· Summer increases in temperature and precipitation may impact the frequency and intensity of hail storms, invasive tree species, and fire management.
· A change in the frequency and duration of extreme precipitation events can lead to the opposing problems of drought and deluge, as well as early fall and late spring snow storms which can bring problems all their own.
The Playa Lakes Joint Venture has agreed to expand its management board and serve as the GPLCC Steering Committee. A draft action plan outlines six high priority landscapes and a number of priority species of interest.
At FORT we will provide technical and applied research support to the Great Plains LCC through the application of landscape ecology, ecosystem science, climate change science and climate adaptation ecology, wildlife biology, conservation genetics, and habitat/population modeling in aquatic and terrestrial systems. Dan Manier's project, "Landscape Assessment of Relations among Land Use, Hydrology, and Wildlife Habitats in the Southern Great Plains Region" proposes to complete a comprehensive landscape assessment of the GPLCC area by aggregating, developing and analyzing spatial datasets and developing statistical models to analyze the correlative and functional relations among land use, hydrology, and wildlife habitat; utilize hierarchically organized map and data classes at a watershed scale to provide locally detailed assessments nested within the GPLCC area to provide locally detailed (relevant) information within a landscape perspective; and establish a spatial framework and data library required for systematic evaluation of Habitat Suitability, land use and climate affects, population dynamics, surface and groundwater hydrology and for conservation, management and research applications.