Communit.v composition wus variuhle and most species responded individual1.y to soil vuriables, partrcularly soil depth and degree and kind of stoniness. Common curl}Jmesquite (Hilaria belangeri) was the most characteristic and widespreud species of the area. Communities dominuted by Texas cupgruss (Eriochloa sericea), on soils greater than 2.5 cm in depth, produced 4

A study was initiated in August 1975 to illuminate the dietary interrelationships among four kinds of small ruminants on the Edwards Plateau of Texas. Sheep diets were dominated by grass followed by browse, goat diets were nearly equal in percent grass and browse, and deer spent most of their feeding time on browse followed by forbs. Livestock diets were not as high in forbs as expected, indicating that abundant grass due to excellent range condition may relieve livestock pressure on forbs, leaving more forbs for deer. Increased feeding time by deer on grass regrowth, after livestock were removed from the study area in July for a 4-month deferment, indicated that grazing systems were favorable to deer by providing regrowth forage. However, where livestock and deer graze in common, there are periods of competition even under excellent range conditions. These periods were fall and winter for browse, winter and early spring for forbs, and anytime immature grass was available. Relative to deer, sheep probably were most competitive for forbs and succulent grass, while goats, particularly the Spanish goats, were most competitive for browse. Similar annual trends for diets for all kinds of animals for all forage classes suggested competition was primarily for palatable green forage.

The influence of short duration grazing (SDG), moderate continuous grazing (MCG), heavy continuous graxlnr (HCG). and communities was evahtated over a 2Ormonth pe& on the Texas Agricultural Research Station, located near Sonora in the Edwards Plateau, Texas. A combination of cattle, sheep, and goats were used in each grazing treatment. Infiltration rates were consistently less in the midgrass (bunchgrass) than in the shortgrass (sodgrass) community. The HCG pasture was severely overgraxed and htfiltration rates were reduced to about one-half those in the MCG pasture. The mldgrasses in this pasture were destroyed after 26 months of overgrazing. Infiltration rates in the SDG pasture, stocked at double the recommended rate, decreased during the study period. Infiltration rates in the SDG pasture shortgrass community, near the end of the study, approached those in the HCG pasture. The greatest infiltration rates for both communities were maintaIned in the MCG pasture. Infiltration rates for the midgrass community remained relatively stable during the study when the general trend in the SDG and HCG pastures was toward reduced infiltration rates. The nongrazed pasture subsequent to the 1980 drought had a general increase in inflltratlon rates.

A study was initiated in August, 1975, to examine the forage available to and diet composition of white-tailed deer on pastures of excellent and poor range condition at the Sonora Research Station near Sonora, Texas. Grass and forb standing crop and deer feeding time on these two forage classes were considerably higher on the pasture in excellent range condition than that in poor range condition. Browse standing crop and feeding time was greater from the pasture in poor range condition. The Merrill 4-pasture grazing system appeared to increase the availability and use by deer of grass regrowth. Yearly averages of crude protein and phosphorus were higher in diet samples collected from the pasture in excellent range condition. Digestible energy levels were similar between pastures when averaged over the l-year period. Digestible energy levels in diets were, however, higher from the excellent condition pasture in every season except winter. In winter, deer fed primarily on the foliage of oak on excellent condition range; but on the pasture in poor range condition, deer used large amounts of foliage and mast from juniper and dead leaves of persimmon in addition to oak foliage. Juniper and persimmon apparently contributed to the higher digestible energy levels observed on the pasture in poor range condition during the winter season. Energy may be a major nutrient limiting deer production on the Edwards Plateau. In pristine times, the Edwards Plateau of Texas was considered a grassland steppe but has since been invaded by woody perennials (Krebs 1972). It now contains a diverse community capable of supporting many kinds of plants and animals. Among the endemic

A study was conducted to evaluate standing crop of forage and cattle diets for a 'I-pasture high-intensity low-frequency (HILF) grazing system, and a 'I-pasture short-duration grazing (SDG) system on the same area. A epasture, 3-herd (Merrill) deferred rotation grazing system was sampled as a standard for comparison. Standing crop of forage was highest for the HILF grazing system compared to the SDG and Merrill grazing systems. The Merrill system with brush control (Pasture 10) had a greater standing crop than the Merrill system without brush control (Pasture 16) or the SDG system. Standing crop in Pasture 16 was comparable to the SDG system. Cattle diets from the HILF system varied significantly between collections at the beginning and end of each grazing period. A significantly higher percentage of forbs were consumed at the beginning of each grazing period (Period A) compared to the end (Period B). Cattle selected the greatest amounts of pricklypear at the end of each collection period during fall and spring, but not during the winter. Greater amounts of pricklypear were selected when mature grasses and oak and juniper browse were the primary alternatives. Crude protein (CP) levels of diets from the HILF system decreased with shifts in forage selection from Texas wintergrass and forbs (Period A) to pricklypear and dry grass (Period B). Diets from the SDG system were characterized by higher percentages of grass and less forbs and pricklypear compared to the HILF grazing system. Also, there were no major shifts in forage selection between collection period A and B for the SDG system. This resulted in a non-significant difference in CP values for diets collected in period A compared to period B. However, a significant decline was recorded for digestibility of diets between the two collection periods. CP and digestibility were higher for diets from the SDG system compared to the HILF grazing system. Botanical composition and diet quality were comparable for the SDG and Merrill grazing systems. Competition between different kinds of animals may be reduced by changing management from a HILF to a SDG system. This would be important where combinations of animals such as cattle, sheep, goats, and deer utilize a common range. Based on diet quality, livestock production from a SDG system should be equivalent to a Merrill system.