Treesearch

The land management agencies of the Department of the Interior (DOI), the National Park Service (NPS), U.S. Fish and Wildlife Service, and Bureau of Land Management are responsible for 51.5 million acres (20.8 million ha), or 71.5% of the nation's designated wilderness. In addition, the NPS generally manages backcountry lands not designated as wilderness for wilderness values. The U.S. Geological Survey (USGS) does not manage public lands, but is the DOI agency responsible for "providing reliable scientific information to describe and understand the Earth; minimize loss of life and...

Chile has an economy strongly based on the exploitation of its natural resources. Copper mining represents the main export monetary income, employing thousands of people all along the country. The Chilean Copper Corporation (CODELCO), El Salvador branch, has been the primary mining company, but it will be ending most of its activities by 2011 unless copper prices stay at their record levels. Besides the job consequences for the local population, there are some serious environmental issues that must be solved during the shut-down.

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads...

Agricultural and municipal water supply interests in Chile rely heavily on streams which flow from the Andes Mountains. The highly productive Copiapo agricultural region, on the southern edge of the Atacama Desert, is a major supplier of fruit and other crops for the Northern American market during winter. This region relies entirely on snow and icemelt streams to provide irrigation water. Santiago, the Chilean capitol, is the country's major metropolitan area with a population of 5.5 million. Rainfall that averages 330 mm/year is nearly twice that of Phoenix.

Amphibian populations continue to be imperiled by the chytrid fungus (Batrachochytrium dendrobatidis). Understanding where B. dendrobatidis (Bd) occurs and how it may be limited by environmental factors is critical to our ability to effectively conserve the amphibians affected by Bd. We sampled 1247 amphibians (boreal toads and surrogates) at 261 boreal toad (Bufo boreas) breeding sites (97 clusters) along an 11 latitudinal gradient in the Rocky Mountains to determine the distribution of B. dendrobatidis and examine environmental factors, such as temperature and elevation, that might...

At the end of the 2007 Fiscal Year, the Experimental Forests and Ranges (EFR) Synthesis Network Committee awarded funds to 18 sites to establish a strategic ICP Level II (described below) synthesis network in the United States. Eleven Experimental Forest were selected to be included in the network, as well as seven Long Term Ecological Research (LTER) sites. This will give the USFS R&D a ICP Level II Network starting this year, the only one in North America (see Appendix). Each site will include a NADP weather station, UV Radiation Monitors and Ozone Sensors. The Sierra Ancha Experimental...

We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlya and Leptolegnia. Our phylogeny grouped S....

The Middle Rio Grande and its riparian forest in central New Mexico are the focus of restoration activities to reverse or lessen negative anthropogenic impacts. The riparian forest is the largest gallery cottonwood (Populus deltoides) forest in the Southwest (Hink and Ohmart 1984). Historically, the river was free to meander across the floodplain, creating a dynamic system in which riparian vegetation establishment on riverbanks alternated with periods of scouring floods (Crawford et al. 1993). The establishment of non-native invasive plants has compounded the impacts of an altered...

Denali National Park and Preserve is an American icon for wilderness. Not everyone accesses wilderness in the same way, however, or has the same experiences. Wilderness recreation experiences at Denali vary tremendously. Interviews with flightseers at the park have created a better understanding of the recreation experiences for these day users and helped us recognize glacier landings in the backcountry as unique aspects of that experience. In self-reports about their visits, day users focused heavily on the unique scale of the wilderness of the Alaska Range, seeing climbers in the park,...

Leaf area index (LAI) is a key forest structural characteristic that serves as a primary control for exchanges of mass and energy within a vegetated ecosystem. Most previous attempts to estimate LAI from remotely sensed data have relied on empirical relationships between field-measured observations and various spectral vegetation indices (SVIs) derived from optical imagery or the inversion of canopy radiative transfer models. However, as biomass within an ecosystem increases, accurate LAI estimates are difficult to quantify. Here we use lidar data in conjunction with SPOT5-derived spectral...