Selection of woody plants by nesting nongame birds was investigated in burns of several different ages in a honey mesquite-tobosagrass community in central Texas. Lotebush and honey mesquite were the most important plants used with nesting activity recorded in 30.3% of all lotebushes inspected. The average volume of 97 occupied lotebushes was 1.6m3. Above-ground age of the smallest plants used averaged 6.1 years. The majority (68.6%) of the lotebushes counted in density plots were resprouts following fires and only 3.0 plants/ha were actually available as nest sites.

The Festuca-Stipa grassland community was found to be well adapted to surviving a single prescribed burn. Coverage of rough fescue was reduced from one to three growing seasons after fire depending upon season burned and stage of growth. Spring burning benefited the production of seed heads in western porcupine grass but fall burning reduced its cover and production of seed heads. Annual herbage production was neither increased nor decreased if burning occurred when plants were dormant. Species composition shifted in favour of perennial forbs for at least 3 years after a burn.

Current and pending legislation will require that lands disturbed by mining activities be revegetated. Since few adapted species are now available for reclamation of such lands in the arid zone, this study was initiated to identify native species that are successful colonizers of disturbed sites. The native vegetation of bladed roadways in the Kane County, Utah, was sampled to identify natural colonizer species. Sixteen successful colonizers have been identified and studied to determine (1) their relative colonizing efficiency, and (2) their individual responses to elevational, soil textural, and other environmental gradients. The species fall into two natural groups: one group is well adapted to lower benchlands with sandy clay loam soils and the other is adapted to upper benchlands with sandy loam soils. Some of the species that appear to be most successful in initially revegetating disturbed areas include: (1) upper benchlands-Indian ricegrass, galleta grass, sand aster, pepperweed, broom snakeweed, small-leaf scarlet globemallow, and blue locoweed; (2) lower benchlands-shadscale, desert molly, cut-leaf globemallow, and pink locoweed.

A wealth of experimental data has been accumulated on quantitative intake of pen-fed livestock; such information has been widely employed to develop a keener nutritional knowledge of such animals. Data of this type are, however, distressingly lacking for grazing livestock. The procedures used for measuring intake by animals under grazing conditions have often been disappointing, and many have provided unreliable data. Forage intake measurements with grazing livestock are more commonly expressed as g DM or OM/W kg^0.75 or simply as a percent of body weight. Most estimates of intake for cattle and sheep grazing ranges in Western United States fall within the range of 40 to 90 g OM/W kg^0.75 or from 1 to 2.8% of body weight. Intake usually decreases with advancing plant maturity.

Shore vegetation around Lakes Oahe and Sakakawea, mainstem Missouri River reservoirs, is a mosaic of shifting plant populations that responds to a combination of limiting factors including water level fluctuations and cattle grazing. Shore vegetation is important as it provides some wildlife habitat and spawning habitat for certain fish species, reduces erosion, adds to the aesthetic value of the shore environment, and provides forage for cattle grazing. The present study was done in 1976 to document the effects of cattle grazing on shore vegetation at seven sites that were inundated for a prolonged period in 1975. Some of the dominant shore species were Horedeum jubatum, Agropyron smithii, A. repens, Chenopodium album, Iva xanthifolia, Kochia scoparia, Melilotus ssp., Polygonum achoreum, P. lapathifolium, Rumex crispus,, and Xanthium strumarium. Solanum rostratum and Grindelia squarrosa along with several other species were favored by grazing. Floristically, ungrazed plots were more similar than grazed plots when pairs of sites were compared. Total plant coverages inside exclosures at three sites on Pierre Shale-derived soils ranged from 54% to 97% and biomass values ranged from 458 g m-2 to 720 g m-2, while outside exclosures at the same sites total plant coverages ranged from 11% to 82% and biomass values were 19 g m-2 to 259 g m-2. At one site, on loess-derived substrate, total plant coverages inside and outside the exclosure were 116% and 77% respectively, and biomass values were 606 g m-2 inside and 210 g m-2 outside the exclosure. All three sites on Lake Sakakawea are on glacial till-derived substrates, and plant coverages ranged from 128% to 155% inside exclosures where biomass values were 478 g m-2 to 1,766 g m-2. Outside the exclosures the total plant coverages were 24% to 144% and biomass values were 15 g m-2 to 474 g m-2. Shore vegetation develops between periods of high water; thus annual fluctuations in water levels, along with cattle grazing as limiting factors, keep shore vegetation in an early seral stage. Minimizing both water level fluctuations and cattle grazing for a given reservoir during a given year, preferably a 2-year period, would permit considerably more shore vegetational development. This regimen, if rotated among the six reservoirs, would over a period of years, benefit development of shore vegetation.

Burning had a minimal effect on rainfall infiltration and sediment load in runoff from a mesquite-tobosagrass community on slopes less than 1%. Most soil physical properties that affect infiltration on these heavy clay soils were not altered significantly by burning. Potential soil loss in runoff can be minimized by burning under relatively moist conditions. Larger soil aggregates were broken down by burning and had not returned to equilibrium on 5-year-old burns. Trends in levels of soil organic carbon, salinity, sodium, and potassium following burning varied with degree of soil cracking, which is a function of soil moisture.

The evolution of multi-camp schemes from nonselective grazing to short duration grazing management on Hillside Ranch in the False Karoo in the Southern Orange Free State, Republic of South Africa, is described. The grazing system resulted in the return and increase of rare and unknown grasses. The conclusion is reached that grazing management with multi-camp schemes is useful in counteracting varying climatic conditions and producing a grass cover under adverse growing conditions. In addition it is shown that livestock can produce well under such systems.

The accuracy and efficiency of the browse biomass estimation for a young forest plantation in central Sweden was compared using two different methods. Using the traditional harvest plot technique, the amount of browse was determined as 40.4 g dry weight/m2; while the new technique gave a similar result, i.e., 36.4 g dry weight/m2. The new method employs the relationship between the height-diameter index of trees and the total biomass of browse per tree as well as the regular twig count. It was found that the new technique is approximately 11 times more efficient than the regular browse harvest technique. The possibility of application of the new method in forest habitats is discussed.