Treesearch

Information on population dynamics is key to gauging the status of threatened or endangered species. We monitored demography of a population of threatened Mexican spotted owls (Strix occidentalis lucida) in the Sacramento Mountains, New Mexico from 2003 to 2011. We estimated reproductive output for territorial pairs of owls; used mark-recapture methodology and Pradel's reparameterized Jolly-Seber models to estimate annual apparent survival rates, recapture rates, recruitment rates, and annual rate of population change (lRJS) for 2005-2009; and used estimates of lRJS to assess short-term...

This report traces the flow of Wyoming’s 2010 timber harvest through the primary wood-using industries; provides a description of the structure, capacity, and condition of Wyoming’s primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as changes in harvest, production, employment, and sales.

Rangelands are lands dominated by grasses, forbs, and shrubs and are managed as a natural ecosystem. Although these lands comprise approximately 40 percent of the landmass of the continental United States, there is no coordinated effort designed to inventory, monitor, or assess rangeland conditions at the national scale. A pilot project in central Oregon with the U.S. Forest Service, the Natural Resources Conservation Service, and the Bureau of Land Management showed how consistent information could be collected to produce approximately unbiased estimates across the landscape. Exploratory...

Reducing atmospheric carbon dioxide (CO2) concentration through enhanced terrestrial carbon storage may help slow or reverse the rate of global climate change. As a result, Federal land management agencies, such as the U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, are implementing management policies to increase carbon storage. However, information on how projected southwestern climate changes might affect the balance between CO2 uptake and loss on semiarid rangelands is not easily accessible to land managers. We summarize...

We monitored snag populations in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa) forests, northern Arizona, at 5-yr intervals from 1997-2012. Snag density increased from 1997-2007 in both forest types, with accelerated change due to drought-related tree mortality during the period 2002-2007. Snag density declined non-significantly from 2007-2012, but median snag density in 2012 remained significantly greater than median density in 1997. Differences in composition of snag populations also persisted through 2012. Our results suggest that the drought-mediated spike in tree...

Climate change impacts many species through shifts in habitat. The intensity of this impact will depend on the dispersal rates of the species, the patchiness of the environment, and the velocity of habitat change. Here we examine how dispersal affects projected future habitat availability for a threatened carnivore, the fisher (Pekania [Martes] pennanti). We used non-invasive genetic sampling to detect fisher across their historical distribution in Montana and Idaho. This survey included 4846 non-invasive hair snares, of which 288 identified fishers through mitochondrial DNA analysis. We...

Pikes Peak Highway is a partially paved road between Cascade, Colorado and the summit of Pikes Peak. Significant gully erosion is occurring on the hillslopes due to the concentration of surface runoff, the rearrangement of drainage pathways along the road surface and adjacent drainage ditches, and the high erodibility of weathered Pikes Peak granite that underlies the area. As a result, large quantities of sediment are transported to surrounding valley networks causing significant damage to water quality and aquatic, wetland, and riparian ecosystems. This study establishes the slope/drainag...

Conservation scientists and resource managers often have to design monitoring programs for species that are rare or patchily distributed across large landscapes. Such programs are frequently expensive and seldom can be conducted by one entity. It is essential that a prospective power analysis be undertaken to ensure stated monitoring goals are feasible. We developed a spatially based simulation program that accounts for natural history, habitat use, and sampling scheme to investigate the power of monitoring protocols to detect trends in population abundance over time with occupancy-based...

Wildland fire is an important natural process in many ecosystems. However, fire exclusion has reduced frequency of fire and area burned in many dry forest types, which may affect vegetation structure and composition, and potential fire behavior. In forests of the western U.S., these effects pose a challenge for fire and land managers who seek to restore the ecological process of fire to ecosystems. Recent research suggests that landscapes with unaltered fire regimes are more ''self-regulating'' than those that have experienced fire-regime shifts; in self-regulating systems, fire size and...

Herbivore-driven changes to soil properties can influence the decomposition rate of organic material and therefore soil carbon cycling within grassland ecosystems. We investigated how aboveground foraging mammalian and invertebrate herbivores affect mineral soil decomposition rates and associated soil properties in two subalpine vegetation types (shortgrass and tall-grass) with different grazing histories.