Browsing Journal of Range Management, Volume 29, Number 2 (March 1976) by Title
Now showing items 21-24 of 24
Stratification of Bitterbrush SeedsThe influence of temperature and moisture availability during stratification on the subsequent germination of bitterbrush (Purshia tridentata) seeds was investigated. The threshold for adequate stratification temperatures was abrupt. Temperatures above 5 degrees C were too warm and below 0 degrees C, too cold for stratification; 2 degrees C was optimum for the longest duration. Prolonged stratification resulted in decreased viability, apparently from microbial activity and early germination. Stratification in osmotic solutions produced with polyethylene glycol was totally ineffective. Soil water stress reduced the effectiveness of stratification, especially with sand as a substrate. Any departure from optimum temperature and moisture regimes prolonged the time required for stratification or negated any effect of the stratification treatment.
Summer Diets of Steers on a Deep Hardland Range Site of the Texas High PlainsBotanical and chemical compositions of the summer diets of esophageal-fistulated steers were determined on a deep hardland shortgrass range site of the Texas High Plains. Consumption of belvedere summercypress was highest in June, but decreased to September; whereas, consumption of blue grama, buffalograss, and sand dropseed increased during this period. Belvedere summercypress was eaten in considerable quantities until it approached dormancy. Dietary crude protein and calcium percentages were highest in June, but declined to September. Daily forage consumption averaged 10.9 kg during June and July. A forage utilization of 17.4% was obtained during the summer grazing period and the steers gained an average of .45 kg/day.
Survival of Cool-Season Species under Texas-Pecos ConditionsFour cool-season species were grown for 1 year under controlled conditions simulating a dry, a typical, and a wet fall planting season in far west Texas. Crested wheatgrass and Russian wildrye had higher survival percentages than sideoats grama at the end of the study. Both species appear capable of reducing the cool-season forage shortage in the Trans-Pecos region of Texas. Neither wintergreen hardinggrass nor burnet appear adapted to the Trans-Pecos. Seedling morphology did not affect plant survival.
Yields of Dissolved Solids from Aspen-Grassland and Spruce-Fir Watersheds in Southwestern AlbertaWater quality samples representing various flow conditions were collected from the main creeks of Streeter and Marmot experimental watersheds in southwestern Alberta. Total dissolved solids were determined gravimetrically after evaporating aliquots of filtered samples. An excellent correlation between stream discharge and yield of dissolved solids was found in the two watersheds. The regression models thus established were used to estimate the yields of total dissolved solids from the streamflow data on a daily, monthly, and annual basis. The highest yield occurred in the month of June and the lowest during the low-flow months of winter. The yield of total dissolved solids transported annually amounted to 27 metric tons per square kilometer for aspen-grassland vegetation, compared to 69 metric tons per square kilometer for spruce-fir forest.