Based on this research and other work that has been reported, honey mesquite is very difficult to kill with fire on the High Plains and along river bottoms in the Rolling Plains. On upland sites in the Rolling Plains, 27% of the mesquite trees were killed following single fires. Using repeated fires on upland sites at 5 to 10 year intervals, the potential exists to kill 50% of the older mesquite trees. Seedlings of honey mesquite were easy to kill with moderate fires until they reached 1.5 years of age, severely harmed at 2.5 years of age, and very tolerant of intense fires after 3.5 years of age.

Seasonal changes in forage production and quality occur due to climatic factors, principally precipitation. Increased efficiency of livestock production could occur if livestock management were coordinated to the changes that occur in forage quality. Traditionally, calves are born in the spring in much of the western United States. Weaning then occurs sometime in late fall. Management practices of early weaning, supplementation on the range, time of calving, and length of the breeding period can be incorporated into a livestock system to take advantage of forage at its highest quality and therefore to maximize beef production from the existing forage resource.

An efficient machine which uses water spray and agitation to separate the roots contained in soil samples from the soil material was constructed from readily available, commercial components for less than $400.

Prairie range forage plants can provide needed energy and protein for grazing ruminants, particularly in an era of grass fattened animals. Nutritive value and, therefore, animal performance, are directly related to stage of plant maturity at the time of cutting or grazing. The effect of maturity of four native species in this study was accompanied by a decline in in vitro dry matter digestibility and protein content, and by an increase in fibrous fractions and lignin. Laboratory analyses of prairie species showed seasonal chemical and digestibility changes similar to those of cultivated grasses. A significant date-by-class interaction suggests that cool-season species did not respond differently to maturity changes than did the warm-season species. The neutral sugars found in hemicellulose were xylose, arabinose, glucose, and galactose. Xylose was the predominant structural sugar in all species studied. It would appear that laboratory analysis could serve to estimate nutritive value of various prairie grasses.

Some ecological relations between creosotebush and bush muhly were observed and measured to determine the influence of bush muhly on creosotebush environment and vigor when the bush muhly is growing within the creosotebush canopy. Bush muhly growing within the creosotebush canopy significantly reduced the light intensity reaching the lower limbs of creosotebush. Shade screens used for simulating bush muhly shading did not significatly reduce the light reaching the creosotebushes but still appeared to influence the new growth of creosotebush leaves. Evidently, surface reflection under the screens still permitted sufficient light for some plant growth. No new basal stem growth was observed in creosotebushes where bush muhly was removed after occupying more than half of the aerial space of the creosotebush. There were more dead stems (50%) in creosotebushes growing with bush muhly present than in those without (20%). The amount of moisture in leaves and stems of creosotebush was significantly less when bush muhly was present.

From 1960 to 1975, a series of trials on the eastern side of the Columbia Basin north of the Snake River was conducted to determine the feasibility of establishing crested wheatgrass on rangelands now dominated by downy brome and medusahead. Excellent annual grass and annual broadleaf weed control was obtained with several herbicides, with atrazine at 1:1 kg/ha as a fallow treatment before seeding being the most satisfactory. Seeding in late autumn or early spring with a rangeland drill, modified to give some seedbed preparation in the row, combined with annual weed control, generally provided favorable conditions for germination and emergence of crested wheatgrass seedlings. However, seedlings failed to become established in most experiments. Trials with a soil fumigant, methyl bromide, resulted in excellent stands of established plants and presented strong evidence that with seedling plants under environmental stress, microbiological factors may be a primary cause of seedling failure.

Protection from grazing, alternate rest, or seasonal spring or fall grazing did not promote recovery of pine-bunchgrass range in Colorado which had been grazed heavily for more than 23 years. Application of 2,4-D herbicide or NPK fertilizer significantly changed vegetative composition and increased herbage yields of these rangelands under all grazing treatments. The herbicide reduced competition from forbs and permitted the grass species to increase in basal area and produce more herbage than plants on unsprayed, unfertilized control plots. Addition of NPK fertilizer stimulated production of all species and increased yields an average of 500 lb per acre. A combination fertilizer-herbicide treatment increased average yields a comparable amount, with the increase coming mostly from grasses and a few forbs not killed by the herbicide.

This paper provides estimates of predation losses of domestic sheep in Alberta in 1974. These estimates were obtained from personal interviews. Unlike the United States, Alberta had a predator control program which emphasized the use of toxicants. Province-wide predation losses averaged 1.6% of the ewes and 2.8% of the lambs. However, predation losses varied widely among five major ecosystems; i.e., between 0.8% of the lambs and ewes in the southern parkland and 3.2% of the ewes in the northern parkland and 6.8% of the lambs in the mixed forest. Predation accounted for 24 and 18% of the total annual mortality of lambs and ewes, respectively. Thirty-nine percent of the flocks had no predation losses and another 31% of the flocks had predation losses of 3% or less. Larger flocks tended to be more susceptible to predation than smaller flocks. Coyotes, dogs, and other large predators were reported to have caused 88, 8, and 4% of predation losses, respectively.

Roots of honey mesquite seedlings produced nodules readily in the growth chamber. The nodulated seedlings contained more nitrogen than nonnodulated seedlings. Large plants had the largest nodules. West Texas soils were found to possess inoculum that caused nodulation in mesquite. The nodulation frequency was closely associated with soil texture and water at the time of collection of the soil inoculum source. Moist sandy soils produced the best nodulation, while dry clay soils produced the poorest nodulation.