Treesearch

The riparian wetland vegetation communities of the upper and middle Rio Grande watersheds in New Mexico were surveyed in 1992 through 1994. The communities are hierarchically classified in terms of species composition and vegetation structure. The resulting Community Types are related to soil conditions, hydrological regime, and temporal dynamics. The classification is part of a comprehensive effort to develop a systematic understanding across the state of the diversity of riparian/wetland communities and how they are influenced by specific hydrologic, edaphic and climatic environments. An...

We provide a summary of vegetation changes over a 11-year period (1 984-1 995) in the middle reach of the Rio Grande. Hink and Ohmart (1984) surveyed and mapped riparian vegetation along the middle Rio Grande as part of an extensive biological inventory conducted for the Army Corps of Engineers. We field-assessed and remapped the Isleta-Belen reach in 1995 to determine whether vegetation classes had changed substantially since the Hink and Ohmart survey. Over the past 11 years, the Rio Grande bosque vegetation has aged, and our assessment of structural types documents this aging process....

We investigated avian species richness and abundance within vegetation communities of the Rio Grande Corridor of New Mexico during spring, summer, and fall 1992 and 1993. A subset of 64 transects, for which all bird and vegetation variables were available, representing 16 composite vegetation community types were subjected to canonical correlation analysis to investigate relative habitat importance. Generally, the higher ranking community types had cottonwood and other native woody species as dominants and the lower ranking communities were those types that are highly manipulated and/or...

The Rocky Mountain Forest and Range Experiment Station initiated a research program in 1994 called. "Ecology, diversity, and sustainability of soil, plant, animal, and human resources of the Rio Grande Basin". This program is funded by an Ecosystem Management grant from Forest Service Research. Its mission focuses on the development and application of new knowledge to sustain ecological systems and human populations in the Middle Rio Grande Basin. Research studies emphasize upland ecology and management, linkages between watersheds and riparian zones, sensitive fish and wildlife populations...

Interest in the condition, role, and sustainability of southwestern riparian ecosystems has increased greatly since the mid 1970's. Reflecting this growing interest is a series of symposia addressing southwestern riparian issues, including those coordinated by Johnson and Jones (1977), Johnson and McCormick (1979), Johnson et al. (1985), and Tellman et al (1993). The proceedings of these symposia tell an important story about the history of riparian ecosystems, documenting changes in water quality, vegetation, fish and wildlife, land use, and human values. Concern for the declining health...

Thank you for your invitation to attend today's panel discussion on "Rio Grande Restoration: Future Directions." I apologize for not being able to attend in person, but I hope you will understand that now is a particularly busy time here in Congress.

The Middle Rio Grande (MRG) riparian forest, or "bosque", represents the largest cottonwood gallery riparian forest in the southwestern United States. This reach of the Rio Grande extends from Cochiti Dam downstream 260 Km to San Marcial, New Mexico. It constitutes 8% of the river’s total length and 34% of if its length in New Mexico. The valley traverses three major biotic communities, as defined by Brown and Lowe (1980). The MRG reach can be subdivided into 4 reaches which coincide roughly with the 4 geologic basins or "grabens" along this portion of the Rio Grande Rift. This system has...

In midwestern steppes, precipitation peaks in summer, whereas west of the Rocky Mountains, steppes are characterized by summer drought. In western deserts, the amount of precipitation is highly variable. These different climatic regimes result in differences in prevalence of and resilience to disturbances such as herbivory, and differences in susceptibility to invasion by exotic plants and animals. The timing and predictability of precipitation influences plant phenology and life forms, which in turn influence the distributions and annual cycles of animals such as bison (Bison bison) and...

In this study, we used a modified version of a meta-analysis (compilation and analysis of the literature in which an individual area is subjected to the disturbance and its response is noted) to analyze grazing effects on grassland ecosystems. Prior efforts have focused on one aspect of ecosystem behavior such as productivity or species diversity. In this analysis, we examined several components of ecosystem function that are seldom explored including measures of nutrient cycling and soil compaction. In general, cattle grazing appears to decrease production measures, increase soil compactio...

The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a management tool. Fire is now used as a management tool on at least a limited scale in all areas of North America, and perhaps nowhere is the role of fire in community organization more widely acknowledged than in grassland ecosystems....