The file contains net aboveground production data for perennial and annual grasses for USFS Study 1706-15. A copy of the Study Plan may be downloaded at http://ag.arizona.edu/SRER/study15/study15.txt. Measurements were taken annually from 1959-1966 in plots located along permanent line transects in two pastures. Transects were established at distances of 100, 200, 300, 400, and 500 yards from each of five water sources. Fifty transects (two sets of five at each water source) were measured in pasture 6A. Ten transects (two sets of five at one water source shared with pasture 6A) were measured in pasture 6B. A water-rotation schedule in pasture 6A specified only one water source to be open at a time. The water source for pasture 6B was open continuously. The study area was grazed yearlong by cattle. Herbage production was estimated to the nearest gram each autumn using double sampling. Field weights were estimated on five permanent 9.6x1 ft. plots and on one temporary plot per transect. Herbage on temporary plots was clipped and weighed to calculate a factor for adjusting ocular estimates. Dry weights of clipped herbage provided a moisture correction factor. Field weights from the permanent plots were converted to grams per 96 sq. ft. plot. Grams per 96 sq. ft. plot were converted to the nearest 0.1 air-dry pound per acre by applying the factors. In this file air-dry pounds per acre amounts are truncated at the decimal point except for amounts of 0.1-0.9, which are recorded as one pound per acre. Totals calculated from file values will generally be lower than ones calculated from field data due to truncation. Taxa were recorded separately to the species level in most cases and sometimes to the genus level only. The OTHERPG code refers to unidentified perennial grass species; ANNGRASS to all annual grass species. Sources of data were the original field data sheets with the following exceptions: 1) Air-dry pounds per acre had not been calculated for 1959 so these amounts were calculated by applying the factors to total grams on the field data sheets. 2) Air-dry pounds per acre had not been calculated for 1960-1961 so these amounts were calculated by applying the factors to grams per 96 sq. ft. plot on the field data sheets.
|Date made available
|KNB Data Repository