You are here

Geology

Publications

While the unique geographic location of the Sky Islands is well recognized as a primary factor for the elevated biodiversity of the region, its unique tectonic history is often overlooked. The mixing of tectonic environments is an important supplement to the mixing of flora and faunal regimes in contributing to the biodiversity of the Madrean Archipelago.
The Wind River old-growth forest, in the southern Cascade Range of Washington State, is a cool (average annual temperature, 8.7°C), moist (average annual precipitation, 2223 mm), 500-year-old Douglas-fir-western hemlock forest of moderate to low productivity at 371-m elevation on a less than 10% slope. There is a seasonal snowpack (November-March), and rain-on-snow and freezing-rain events are common in winter.
We monitored changes in vegetation and channel morphology along reaches of two perennial streams, Limestone Canyon and East Cedar Creek, on the White Mountain Apache Reservation in Arizona starting in the fall of 1995. Enormous wildfires caused extensive erosion and runoff in the watersheds containing the sites in 2002 and 2003, respectively.
The variability of topography, geology, climate; vegetation, and land use in the Pacific Northwest creates considerable spatial and temporal variability of fluvial processes and reach-scale channel type. Here we identify process domains of typical Pacific Northwest watersheds and examine local physiographic and geologic controls on channel processes and response potential in the Puget Sound region.
The four study areas, located within the Unglaciated Allegheny Plateau of southern Ohio, are underlain predominantly by sandstones and shales of Pennsylvanian Age. The bedrock underlying the Arch Rock (AR), Watch Rock (WR), and Young's Branch (YB) study areas also contain economically important coal strata, while those of the Bluegrass Ridge (BR) study area have significant interbedded limestone layers.
We quantified Mg:Ca, Mn:Ca, Sr:Ca, and Ba:Ca molar ratios from an area representing the summer 2000 growth season on otoliths and scales from 1-year-old westslope cutthroat trout Oncorhyncus clarki lewisi collected from three streams in the Coeur d'Alene River, Idaho, system.
Forests of the semiarid and arid zones of the interior western United States (US) are some of the most unique in North America. They occupy 11 to 34% of the landscape at mostly higher elevations (USDA Forest Service, 1981). These forests are characterized by a high diversity of flora, fauna, climates, elevations, soils, geology, hydrology, and productivity.
In south-central Utah, lands within and adjacent to Capitol Reef National Park contain populations of nine rare plant species. In an effort to enhance the combined knowledge about these species, the Bureau of Land Management, the USDA Forest Service, and the National Park Service signed an Interagency Agreement and hired an interagency biologist and field crew to conduct field surveys for each of these species.
Activities were initiated by The Nature Conservancy, the USDA Forest Service, and the Northern Arizona University School of Forestry and Department of Geology in 1996 to restore hydrologic and ecological function to a high-elevation Bebb willow (Salix bebbiana) and mixed grass riparian community in Hart Prairie, near Flagstaff, AZ.
The attributes of 20 ponds (or stock tanks) on the Nogales Ranger District of the Coronado National Forest were studied in detail by groups. Two contrasting groups, judged to be either functional (n = 11) or nonfunctional (n = 9) were used in the study. Differences between the groups were evaluated on the basis of attributes of the ponds themselves, the contributing watersheds, and the local climate and modeled hydrology.

Pages