Treesearch

The Malpai Borderlands Group, Animas Foundation, other private organizations, and federal and state agencies are concerned about landscape fragmentation, declining productivity, and loss of biological diversity related to encroachment of woody species. In response, they are attempting to implement ecosystem management on almost 1 million acres of grasslands and woodlands in southeastern Arizona and southwestern New Mexico. Reintroduction of natural fire is an important component for achieving ecosystem sustainability. A number of government and private organizations are supporting or...

The International Arid Lands Consortium (IALC) was established in 1990 to promote research, education, and training for the development, management, and restoration of arid and semi-arid lands throughout the world. One activity of IALC members and cooperators is to support research and development and demonstration projects that enhance management of these fragile ecosystems for sustainable human use. Topics of interest include more effective water and watershed management practices, projects, and programs leading to better land stewardship in the coming century.

Inappropriate land uses have degraded wetland and riparian ecosystems throughout the Southwestern United States. In 1996, the Cibola National Forest in New Mexico implemented a channel relocation project, as part of a road improvement project, to determine the feasibility of restoring wet meadow and riparian ecosystems degraded by inappropriately located roads and drainage structures. Results show that channel relocation can provide the hydrologic inputs needed to restore these degraded ecosystems.

Watershed managers and scientists throughout the world have been aware of fire-induced water-repellent soils for over three decades. Water repellency affects many hydrologic processes, including infiltration, overland flow, and surface erosion (rill and sheet erosion). This paper describes; the formation of fire-induced water-repellent soils, the effect of soil water repellency on infiltration and runoff, erosional processes unique to water-repellent soils, and the results of watershed and plot studies used to evaluate watershed-level responses to water repellency.

An important objective of studying understory/ overstory relationships is to determine the patterns of succession or development within the understory plant community following a severe disturbance to the overstory. In 1988, a commercial fuelwood harvest was applied to a pinyon-juniper stand. The remaining noncommercial overstory was cut and lopped. Two years later, approximately two-thirds of the area was crushed by a roller-chopper, which breaks up the slash material and incorporates it into the soil.

As part of the 1998 Joint USDA/USDI Fire Science Program, the Fire and Fire Surrogates Study was proposed to establish and evaluate cross-comparisons of fuels treatment practices and techniques to reduce wildfire risk. This study evaluates prescribed fire, thinning, and various mechanical treatment methods for treating, removing, or using woody biomass. Site-specific and study-wide evaluations will assess watershed impacts, soil disturbance, vegetation responses, wildlife changes, ecological consequences, social impacts, economics, and potential effects on wildfire size, severity, and...

A process-based, simulation model for evaporation, soil water and streamflow (BROOK903) was used to estimate soil moisture change on a semiarid rangeland watershed in southeastern Arizona. A sensitivity analysis was performed to select parameters affecting ET and soil moisture for calibration. Automatic parameter calibration was performed using a procedure based on a Gauss-type downhill search algorithm and a least squares objective function. Results indicated that BROOK90 can be used to simulate changes in soil moisture content in the upper 15 cm on semiarid rangeland environments, an...

An integrated hydrologic modeling/watershed assessment tool is being developed to aid in determining the susceptibility of semiarid landscapes to natural and human-induced changes across a range of scales. Watershed processes are by definition spatially distributed and are highly variable through time, and this approach is designed to account for their spatial and temporal variability. This tool will integrate geographical information systems and distributed hydrologic models in a user-friendly graphical environment. The hydrologic models work under a watershed analysis framework to...

The relationships and interactions of stream courses, their watersheds, and their aquatic biota have become a contemporary paradigm. Principles and practices of these relationships are generally understood, however, understanding their implications at a landscape scale is embryonic. Because of the threatened and declining status of the native fish fauna of the Southwestern United States, understanding relationships between fish and watershed condition, and the influence of watershed management on stream habitats is critical. The native fish fauna of the American Southwest are low in...

The past 4 years the Arizona Water Protection Fund provided more than $25 million to individuals and organizations for stream and riparian restoration projects in Arizona. Information which increases the awareness of the value of Arizona's riparian systems is crucial to the incorporation of ecosystem services into decision-making frameworks, which are largely structured in economic terms. Many individuals reject an anthropocentric perspective of the measure and valuation of ecological goods and services believing they should be protected for purely moral or aesthetic reasons. Others argue...