Treesearch

Dispersal among breeding sites in territorial animals (i.e. breeding dispersal) is driven by numerous selection pressures, including competition and spatiotemporal variation in habitat quality. The scale and trend of dispersal movements over time may signal changing conditions within the population or on the landscape. We examined 2,158 breeding dispersal events from 694 male and 608 female individually marked Northern Spotted Owls (Strix occidentalis caurina) monitored over 28 yr on 7 study areas to assess the relative importance of individual (sex, experience), reproductive (annual...

The life-and-death stakes of predator–prey encounters justify the high price of many anti-predator behaviors. In adopting these behaviors, prey incur substantial non-consumptive costs that can have population-level consequences. Because prey knowledge of risk is imperfect, individuals may even adopt these costly behaviors in the absence of a real threat. For example, rather than only avoid hunters, many species categorically avoid all anthropogenic activity. Although hunting seasons only increase risk for specific individuals (e.g., males), non-target individuals may still perceive human...

Keys to Greater Sage-Grouse (Centrocercus uropha-sianus) management are maintenance of expansive stands of sagebrush (Artemisia species [spp.]), especially varieties of big sagebrush (Artemisia tridentata) with abundant forbs in the understory, particularly during spring; undisturbed and somewhat open sites for leks; and healthy perennial grass and forb stands intermixed with sagebrush for brood rearing. Within suitable habitats, areas should have 15–25 percent canopy cover of sagebrush 30–80 centimeters (cm) tall for nesting and 10–25 percent canopy cover 40–80 cm tall for brood rearing...

Biomass mapping is used in variety of applications including carbon assessments, emission inventories, and wildland fire and fuel planning. Single values are often applied to individual pixels to represent biomass of classified vegetation, but each biomass estimate has associated uncertainty that is generally not acknowledged nor quantified. In this study, we developed a geospatial database of wildland fuel biomass values to characterize the inherent variability within and across major vegetation types of the United States and Canada. For vegetation types that had sufficient quantification...

Family forest owners own more forestland in the United States than any other group. There have been no national studies of racial and ethnic minority family forest owners in the United States, in spite of increasing attention to diversity in forestry. Using the US Forest Service's National Woodland Owner Survey data, we sought to better understand minority owners by looking at their characteristics, attitudes, and behaviors. Of the over 4 million family forest ownerships with 10+ ac in the United States, minorities comprise 6.6 percent of the ownerships and own 5.1 percent of the 265...

Since the 1930s, the United States Forest Service Forest Inventory and Analysis (FIA) program has inventoried the nation’s forests to produce “The Nation’s Forest Census.” This census provides valuable snapshots of forests in the lower 48 states, Hawaii, southeast Alaska, and the U.S.-affiliated Pacific Islands. Although select areas of interior Alaska have been inventoried, a systematic inventory hasn’t been conducted due to the interior’s remoteness and correspondingly higher inventory costs.A team composed of researchers with the U.S. Forest Service Pacific Northwest Research Station,...

Agricultural landscapes in south Asia have high human densities, experience year-round cropping, and the few remaining wetlands experience heavy human use. Factors affecting the breeding success of colonially-nesting waterbirds in such conditions are poorly understood. Using Bayesian Network (BN) models, we explored the importance of colony size, extent of persisting wetlands, human influence as proximity to habitation, and variation in landscape conditions due to changing crops (season) on the breeding success of two stork species – the Asian Openbill Anastomus oscitans and the Lesser...

The magnitude of sediment yield following forest timber harvest is controlled by increases in both sediment supply and streamflow. Since the relation between sediment transport and streamflow typically follows a power law, small increases in streamflow may translate into large increases in sediment transport. Interpreting the geomorphic effects of streamflow increases is confounded by the fact that timber harvest influences both the hydrologic regime and sediment supply of a watershed simultaneously, making it difficult to isolate the streamflow effect alone. Here we report on a novel...