Treesearch

Integrated surface management techniques for pipeline construction through arid and semi-arid rangeland ecosystems are presented in a case history of a 412-mile pipeline construction project in New Mexico. Planning, implementation and monitoring for restoration of surface hydrology, soil stabilization, soil cover, and plant species succession are discussed. Planning phases included baseline survey for native plant community composition and noxious weed populations, seed mixture design, critical area identification, construction specifications for seeding, weed control and erosion controls,...

Restoration techniques for riparian habitats in the Southwest are being widely studied. Efforts for natural regrowth of native species are a high priority. Techniques for native cottonwood (Populus fremontii) regeneration are being investigated in the Rio Grande Valley State Park. Experimentation with flooding of riparian zones using different techniques is beginning to show promising results.

The Bureau of Reclamation routinely mows vegetation on side bars along the Rio Grande to assist with river flow management. To address the question of how such mowing affects vegetation composition and structure, three bars in the middle Rio Grande near Albuquerque, New Mexico were selected in 1994 for an experimental mowing program. Three 50-foot-wide strips on each bar were left unmowed, with the area between the strips mowed as usual. This mowing pattern was repeated in 1995 and 1996. In August 1996, vegetation composition, abundance and structure were measured under the two conditions...

Although watersheds are not equally healthy, there are no generally accepted criteria for evaluating and comparing them. This paper suggests several criteria which numerically evaluate watersheds in four ways: (1) riparian health, (2) aquatic macroinvertebrate biodiversity, (3) hillslope soil loss and (4) upland land use/flood peak potential. Each criterion is semiquantitatively evaluated on a scale of 1 to 10, with 1 the healthiest and 10 the least healthy. The index is applied to two subalpine watersheds near Santa Fe, New Mexico, comparing them using the four numerical criteria. The Rio...

Improving primary roads in the Zuni Mountains of New Mexico must take into consideration the wet meadows and upland areas. This study looks at spring flow rates, erosion, channels and changes in plant cover and composition. The goal is to help planners design environmentally sensitive roadways for wet meadow areas.

This paper is the final report in a larger study of water relations in pinyon pine ecosystems. This last study looks at wholetree response to climatic variability; water use efficiency was studied using 13C measurements of tree-rings.

We conducted an analysis of land cover change in selected piñon-juniper woodlands of New Mexico and Arizona, using aerial photographs from the 1930's through the 1980's. Both increases and decreases in woodland cover were observed. Fractal dimensions of woodland patches and cover-type changes were analyzed following the method of Krummel and others (1987). The analysis failed to identify the scale of anthropogenic disturbance, although land cover change is clearly due in part to human activity. The analytical method may be an insensitive indicator in these woodland systems because the...

Previous publications discussed the results of my dissertation research on relationships between seasonality in precipitation and vegetation patterns at landscape scale. Summer precipitation at a study site in the Zuni Mountains, NM, was predicted from lightning strike and relative humidity data using multiple regression. Summer precipitation patterns were mapped using a Geographic Information System (GIS). Winter precipitation and vegetative cover were obtained from the Terrestrial Ecosystem Survey (TES). Finally, winter and summer precipitation amounts and their percent of annual...

The majority of upland ecosystems (desert scrub, grassland, pinyon-juniper, ponderosa pine and higher elevation conifer forests) in the Middle Rio Grande Basin were historically dependent on periodic fire to maintain their composition, productivity, and distribution. The cultural practices of European man have altered the function, structure, and composition of virtually all Middle Rio Grande Basin ecosystems. Centuries of widespread livestock grazing has altered natural fire frequencies and intensities in upland habitat types. Fire suppression has lead to an increase in woody plant...

Land-use practices such as livestock grazing influence the structure and function of riparian/stream ecosystems. In New Mexico, four streams were selected to determine the impact of moderate livestock grazing on morphology, solute transport, and nutrient retention. Each stream contained a reach currently exposed to grazing and an exclosed, ungrazed reach. Channel width/ depth ratios and in-stream standing stock of plant biomass were greater in the grazed reaches. Solute transport was determined by injecting a conservative tracer (NaBr) and applying a one-dimensional transport with inflow...