File: cover25.xls


The file contains perennial grass basal cover and shrub foliar cover data collected for USFS Study FSRM 1706-25. A copy of the Study Plan may be downloaded from the web site.

Measurements were taken every three years from 1975-1984 on permanent 100-ft. line transects in 12 pastures. Ten transects were measured in pastures 1, 2N, 2S, 3, 5N, 5S, 8, 12B, 21, and 22. Twenty-five transects were measured in pasture 6A and 20 transects in pasture 6B.

Shrub cover was measured every three years from 1975-1984; perennial grass cover in 1984 only.

Pastures were grazed either yearlong or according to a Santa Rita three-pasture rotation system.

Pastures were blocked by elevation -- high (1150-1340 m), intermediate (1040-1220 m), or low (880-1040 m).

Mesquite treatments on transects established for earlier studies are coded in the file as follows: DEAD for mesquite (Prosopis velutina) killed in USFS Studies FSRM 1706-09 and 1706-12, and LIVE for transects on which mesquite was left untreated.

Cover was recorded in units of 0.01 ft. on the field data sheets and in the file. Perennial grass was recorded as basal intercept; i.e., length of live root crown portion of tuft at ground level. Shrub cover was recorded as the entire live crown intercept excluding conspicuous openings or areas of dead crown.

Taxa were recorded separately to the species level in most cases and sometimes to the genus level only. The code OTHSHRUB refers to unidentified shrub species. In this study ARIS refers to tall Aristida species (specifically Aristida hamulosa and Aristida ternipes).

Source of data was an ascii text file prepared from the original field data sheets.

A value of -9999 in a field means that no data were available because a reading was not made for that date.



cov25notes.txt
26 October 2001