File: den25.xls


The file contains density data 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 1972-1984 in permanent 1x100 ft. belt 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.

Perennial grass and shrub density were first measured in 1972; forb density was first measured in 1975.

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 or FSRM 1706-12, and LIVE for transects on which mesquite was left untreated.

Density was recorded as number of plants per 100 sq. ft. on the field data sheets and in the file.

Taxa were recorded separately to the species level in most cases and sometimes to the genus level only. The codes OTHERPG, OTHFORB, and OTHSHRUB refer to unidentified perennial grass, forb, and shrub species. In this study ARIS refers to tall Aristida species (specifically Aristida hamulosa and Aristida ternipes).

Sources of data were the original field data sheets.

Transects 6B-57 and 6B-58 were relocated on 11 July 1975. In 1972 data for these two transects were recorded at different locations.



den25notes.txt
26 October 2001