Treesearch

The spatial and temporal scope of environmental change anticipated during the next century as a result of climate change presents unprecedented challenges for fish and wildlife management. The Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC 2007) suggested impacts from climate change on natural systems will be more grave than earlier projections. Recent reports on emissions, glacial melting, and sea level rise (Kintisch 2009) intimate that even the 2007 IPCC report is conservative in its assessment. The challenges posed by climate change cut across all aspects of...

Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates that are comparable across different species, ages, habitats, sexes, etc. Increasing interest in evaluating the effects of management practices on animal populations in an experimental context has led to a need for suitable...

Since 2001, the USDA Forest Service (USFS) has used classification and regression-tree technology to map USFS Forest Inventory and Analysis (FIA) biomass, forest type, forest type groups, and National Forest vegetation. This prior work used Cubist/See5 software for the analyses. The objective of this project, sponsored by the Remote Sensing Steering Committee (RSSC), was to evaluate other software packages, including R, SAS, WEKA, and Orange. These software packages must work with the USFS standard remote-sensing and GIS packages such as ArcGIS and ERDAS Imagine. As part of this project, a...

Prescribed fire is a commonly used management tool in fire-suppressed ponderosa pine (Pinus ponderosa) forests, but effects of these fires on birds are largely unstudied. We investigated both direct and indirect impacts on breeding birds in ponderosa pine forests of the southern Sierra Nevada where fires were applied in the spring. Following prescribed fire, we found that the largest losses of snags, including the large ponderosa pine snags preferred for nesting, were during the first application of fire after a long fire free interval, while net losses after the second fire application...

Avian populations were monitored using point counts from 2002 to 2007, two years before and four years after a 2800 ha fuel reduction project. The study area was within a ponderosa pine forest near Santa Fe, New Mexico, USA. Adjacent unthinned areas were also monitored as a reference for population variation related to other factors. For individual bird species populations, response generally only lasted one or two years and many species had no response despite the alteration of forest structure from greater than 1240 trees ha-1 to approximately 190 trees ha-1. Response varied by species...

Despite widespread efforts to avert wildfire by reducing the density of flammable vegetation, little is known about the effects of this practice on the reproductive biology of forest birds. We examined nest-site selection and nest survival of the Black-chinned Hummingbird (Archilochus alexandri) in New Mexico riparian forests treated or not for fuel reduction. In untreated plots the hummingbirds frequently nested in exotic trees such as saltcedar (Tamarix spp.) and Russian olive (Eleagnus angustifolia). Following fuel reduction, they increased use of cottonwood (Populus deltoides ssp....

Although there is evidence that interspecific hybridization can initiate invasion by nonnative plants, there are few documented examples of novel hybridization events between introduced plant species already exhibiting invasive behavior. We conducted morphometric and molecular analyses of toadflax plants with intermediate morphology found at two sites in Montana, which were co-invaded by yellow toadflax and Dalmatian toadflax. Field-collected putative hybrid plants had intermediate morphometric scores (mean 0.47, on a scale of 0.0 5 indistinguishable from Dalmatian toadflax to 1.0 5...

Quantifying root biomass is critical to an estimation and understanding of ecosystem net primary production, biomass partitioning, and belowground competition. We compared 2 methods for determining root biomass: a new soil-coring technique and traditional excavation of quantitative pits. We conducted the study in an existing Joint Fire Sciences demonstration area in the central Great Basin. This area is representative of a shrub (sagebrush) ecosystem exhibiting tree (pinyon and juniper) encroachment. The demonstration area had a prescribed burn implemented 4 years prior to our study, and...

Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers often lack fundamental information on the location, quantity, and status of aspen stands. This information is needed to plan, implement, and defend aspen restoration activities, but it is often difficult and costly to obtain....

This study explores potential adaptation approaches in planning andmanagement that theUnited States Forest Servicemight adopt to help achieve its goals and objectives in the face of climate change. Availability of information, vulnerability of ecological and socio-economic systems, and uncertainties associated with climate change, as well as the interacting non-climatic changes, influence selection of the adaptation approach. Resource assessments are opportunities to develop strategic information that could be used to identify and link adaptation strategies across planning levels. Within a...