Changes in rangeland vegetation integrate the consequences of livestock grazing intensity and possible climate change, as well as other factors. Because vegetation changes tend to be very slow in dry environments, observational time scales that exceed a human generation are needed to separate real trends from year-to-year, weather-driven variability. An exhaustive literature search for valid starting points within the Intermountain region revealed a unique quantitative study that was more than 50 years old. In 1933, vegetation along a 37-km transect in southern Pine Valley, Utah, was read from 19-m2 plots located every 42 m. The only intentional, local management treatment in the interim has been moderation of domestic livestock grazing pressure. During a period climatically and phenologically similar to the original study, we re-examined representative segments of this transect by a more detailed updating of the original "square-foot-density" method. We found that vegetation type boundaries and ecotones were little changed after 56 years. However, canopy cover was dramatically greater in 1989, in some cases by more than tenfold for several perennial grasses, and less so for shrubs. Substantially greater understory cover as a relative proportion of total plant cover occurred in 1989 in all vegetation types examined. Some of the observed positive shifts of dominance/diversity are contrary to widely accepted expectations in the literature.

We evaluated winter weight gain of captive male white-tailed deer (Odocoileus virginianus) that grazed pastures of berseem (Trifolium alexandrinium L.), white (T. repens L.), crimson (T. incarnatum L.), or subterranean (T. subterraneum L.) clover their first winter and pastures of berseem, white, or crimson clover or Italian ryegrass (Lolium multiflorum Lam.) their second winter. Weight gains the first winter (14.7 +/- 0.7kg) did not differ (P>0.10) among the clovers. Bucks that grazed berseem, white, or crimson clover the second winter gained 3.0 +/- 0.5 kg, while bucks that grazed Italian ryegrass gained 0.9 +/- 0.9 kg.

Editorial reply to "Viewpoint: sample adequacy for point analysis depends on the objectives," Journal of Range Management, vol. 45, no. 6, p. 595.

Honey mesquite (Prosopis glandulosa Torr. var. glandulosa populations continue to expand and become more dense, even on areas once "successfully" treated either with herbicides or by bulldozing in southern New Mexico. Areas treated from 1958-1964 for mesquite control on the USDA-ARS Jornada Experimental Range and the New Mexico State University College Ranch were sampled to determine mesquite density changes. On herbicide treated areas sampled in 1976 and again in 1988, mesquite densities increased 10% to 128% and had densities from 67 to 494 plants/ha. Two areas treated by either bulldozing or fenuron in 1959-60, and with original kills near 100%, had an average density of 377 plants/ha by 1988, with an establishment rate of 13.5 plants/ha/year. On the College Ranch, mesquite densities increased 11%, from 130 (1982) to 147 (1988) plants/ha. Only 19% of a cohort of mesquite seedlings which germinated in 1989 were still alive in May 1990. Even though only a small percentage of the mesquite that germinated survived into the second year, this is enough to change former grasslands into mesquite-dominated rangelands.

Nutritional quality of range plants eaten by white-tailed deer (Odocoileus virginianus Raf.) in southern Texas is lowest during summer and fall. Nutritional quality of shrub regrowth is typically elevated for several months following top growth removal. We tested a strategy to temper the summer-fall decline in nutritional quality of guajillo (Acacia berlandieri Benth.) and blackbrush acacia (A. rigidula Benth.) by roller chopping separate, adjacent portions of the habitat each year during early July. Parallel strips of brush 40-m wide and about 1.6 km-long were roller chopped during 1986-87 in a pattern of alternating roller-chopped and nontreated strips. Leaves and twig tips of nontreated plants and of regrowth from roller-chopped plants were collected bimonthly and analyzed for crude protein (CP) and in vitro organic matter digestibility (IVOMD). Crude protein of guajillo leaves and stems was higher for regrowth than for nontreated plants for 6 and 8 months, respectively, after roller chopping in 1987, and IVOMD of leaves increased for 2 months. The CP of blackbrush leaves from regrowth was higher than CP of leaves from nontreated plants for 6 months after roller chopping in 1987 but IVOMD temporarily decreased. Roller chopping in early July may temporarily increase CP of guajillo browse during the late summer and early fall nutritional stress period, but it is not a promising method for rejuvenation of blackbrush browse.

Nine yearling Holstein steers (avg weight 234 kg) were used to evaluate the influence of water salinity on feed and water intake, as well as several ruminal and serum characteristics. The ruminally cannulated steers were individually fed low-quality mixed hay simulating a range diet. Steers were assigned randomly to receive either control (C) water containing 350 ppm total dissolved solids (TDS) or a treated water (HS) containing 2,300 ppm TDS. The experiment included a 14-day adjustment period and a 15-day measurement period. High-saline water did not affect (P = 0.18) feed or water intake, although there was a tendency for greater consumption of both feed and water in HS steers. The HS steers had slower (P = 0.10) particulate passage rates and longer (P = 0.06) rumen retention times on day 1 of the measurement period, indicating possible differences in particle density and (or) particle size. On day 1, undigested dry matter (DM) fill was greater (P = 0.05) in HS steers compared with C (80.7 vs 61.5 g/kg BW); similar trends occurred on day 8. The HS steers also had greater (P = 0.02) rumen fluid volumes, but similar (P = 0.45) fluid dilution rates compared with C steers. No in situ DM disappearance differences were detected (P greater than or equal to 0.38) at incubation times ranging from 12 to 72 hours. No clinical or sub-clinical toxicological symptoms were observed in HS compared with C steers. This study suggests that cattle can ingest saline water containing 2,300 ppm TDS on a short-term basis with no adverse effects.

Caldén (Prosopis caldenia Burk.) is one of the woody species that is increasing in abundance due to poor grazing management in the semiarid region of central Argentina. The objectives of this work were to evaluate emergence and seedling survival of caldén under grazed-low herbaceous foliar cover, and ungrazed-intermediate and ungrazed-high herbaceous foliar cover. Seedling emergence was recorded weekly after 3 planting dates: October 1987, September 1988, and October 1989. Seedling survival was recorded every 2 weeks until all seedlings died. Precipitation, soil water potential, and soil temperature were monitored during the study period. Since caldén only reproduces from seeds, optimal conditions for germination under different controlled photoperiod and temperature regimes were also studied. In the laboratory, greatest germination of freshly harvested unscarified seeds occurred at a diurnally alternating temperature regime of 15 and 30 degrees C with light provided for 9 hours. Lead germination occurred at 15 degrees C and continuous darkness. Acid scarification significantly increased germination percentage and germination rate. Unscarified seeds incubated in light exhibited a lower rate of germination than scarified seeds under all temperatures. In the field, soil water availability was usually similar among the 3 experimental conditions. Soil temperature was only occasionally higher in the grazed-low herbaceous cover site. Only for 1987 data, emergence was greater on the grazed area with relatively low herbaceous foliar cover and similar within the ungrazed area. Treatment effect was very little on seedling survival, being lower in the grazed area for only 2 evaluation dates in 1989. Regardless of treatment the emerged seedlings survived 40 days on the average. The highest caldén seedling mortality was always coincident with higher soil temperature and lower soil water availability.

Thirteen grazing studies have recently documented diet botanical composition of cattle in tall forb plant communities on mountain rangelands. In forb-dominated plant communities, cattle selected forbs in proportion to their availability, (46 to 83% of their diets). In grass-dominated communities, forbs comprise only 11 to 32% of diets. On a landscape scale cattle preferred and spent proportionally more time grazing in forb-dominated communities. Taken together, these studies indicate that cattle have a wide acceptability for forage classes and can effectively utilize forb-dominated high mountain rangelands.

A study was conducted in the South Texas Plains to contrast the short-term impacts of short duration grazing (SDG) and deferred-rotation grazing (DG) systems on habitats for northern bobwhites (Colinus virginianus). Foliar cover, species richness, and structural attributes of the vegetation were compared at radio-location sites (quail-used) and sites along random transects (available) within and between the 2 grazing systems. Quail-used sites were characterized by increased species richness, forb cover, and bare ground and decreased plant height and litter accumulations. Principal components analysis revealed that available sites on the SDG during the fall and winter were scored higher along a habitat gradient which had greater species richness and forb cover combined with diminished litter accumulations. This habitat gradient explained 41% of the variation in the ground layer variables. In addition, mark-recapture studies suggested positive population responses on the SDG during the first year following its initiation. Short-term improvements in bobwhite habitats may be realized by initiating SDG on some semiarid rangelands.