Treesearch

Interactions within populations at the periphery of a species' range may depart from those in populations more centrally located. Throughout its core range, limber pine (Pinus flexilis, Pinaceae) depends on Clark's nutcrackers (Nucifraga columbiana, Corvidae) for seed dispersal. Nutcrackers, however, rarely visit the Pawnee National Grassland peripheral population of limber pine on the eastern Colorado plains. Using live mammal trapping, fluorescent pigment tracking of disseminated seeds, and limber pine seed germination experiments in the field, we tested the hypothesis that limber pine...

ECO-Report is an annual Rocky Mountain Research Station (RMRS) publication which contains a set of articles showcasing the Bitterroot Ecosystem Management Research Project (BEMRP) research projects and activities. The articles are concise, user-friendly, and designed to inform a broad range of audiences interested in ecosystem management. Articles featured in this issue: Scale Matters - Some Thoughts on Landscape Sustainability; Visualizing a Forest Landscape Today and Tomorrow; Ecology Research - Something Old, Something New; Economics Research Unit Explores Biomass Utilization Opportuniti...

The Rocky Mountain Research Station is one of six regional units that make up the USDA Forest Service Research and Development organization - the most extensive natural resources research organization in the world. We maintain 12 field laboratories throughout a 14-state territory encompassing the Great Basin, Southwest, Rocky Mountains, and parts of the Great Plains. The Station employs nearly 500 permanent full-time employees, of which over 100 are research scientists.

Canebrakes are dense stands of Arundinaria gigantea (Walt.) Muhl. that covered large areas of the southeastern North America. With agricultural development, canebrakes were quickly converted to crop and pastureland and now occur only in small, isolated patches. There is growing interest in the use of A. gigantea and other temperate bamboo species in riparian and floodplain revegetation in North America, but lack of detailed information on propagation and management of woody perennial grasses hinders reestablishment activities. Our study assesses the influence of nutrient and woodchip mulch...

The Crooked Creek Barrens Preserve in the northeastern Knobs region of Kentucky contains an aggregation of species-rich grass and forb-dominated glade openings surrounded by secondary forest. Encroachment of woody species and invasion by non-native species threaten the rare forbs and sedges of the glades. The locations of these plant assemblages are commonly known to correspond to the unique properties of their underlying soils, yet few studies consider how soil factors may influence habitat conservation or restoration. This study describes vegetation and soil properties across the...

From 1999-2001, a male Canada lynx engaged in yearly exploratory movements across the greater Yellowstone area including the Teton Wilderness Area and Yellowstone National Park. For three consecutive summers, the lynx traversed a similar path in a northwesterly direction from the animal’s home range in the Wyoming Range near Big Piney, Wyoming, to as far as the Henry’s Lake Mountains, west of West Yellowstone, Montana. The longest travel distance was a minimum of 728 km during the summer of 2001. The male crossed several two-lane highways during his movements, including one highway that...

We tested the efficacy of three methods (historical nest search, broadcast search, and tree transect search) for detecting presence of the Northern Goshawk (Accipiter gentilis) at occupied nest areas during the 1994 breeding season using only a single visit to a previously known nest area. We used detection rates in a probability model to determine how many visits are required to have confidence in reporting absence of goshawks. The purpose of this study is to understand if the three methods for detecting goshawks are robust enough for managers to rely on them for making land management...

The advancing role of Global Positioning System (GPS) technology in ecology has made studies of animal movement possible for larger and more vagile species. A simple field test revealed that lengths of GPS-based movement data were strongly biased (P<0.001) by effects of forest canopy. Global Positioning System error added an average of 27.5% additional length to tracks recorded under high canopy, while adding only 8.5% to open-canopy tracks, thus biasing comparisons of track length or tortuosity among habitat types. Other studies may incur different levels of bias depending on GPS sampling...

Yellowstone National Park is hallowed ground when it comes to wildlife in America. The very word “Yellowstone” conjures up images of grizzly bears digging tubers, bands of elk dotting the landscape, and gray wolves pursuing elk along the Lamar River. However, Yellowstone also provides habitat to one of the rarest cats in the continental United States: the Canada lynx (Lynx canadensis). The image of lynx stalking the forests of Yellowstone is absent from most people’s minds because the cat is rarely observed and its life history is poorly understood in and around the park.

Classical biological control of weeds currently operates under the assumption that biological control agents are safe (i.e., low risk) if they do not directly attack nontarget species. However, recent studies indicate that even highly host-specific biological control agents can impact nontarget species through indirect effects. This finding has profound implications for biological control. To better understand the causes of these interactions and their implications, we evaluate recent case studies of indirect nontarget effects of biological control agents in the context of theoretical work...