APPENDIX D
HISTORICAL MAPS OF THE SANTA RITA EXPERIMENTAL RANGE
LIST OF FIGURES AND CAPTIONS:
- Location of the Santa Rita Experimental Range.
- Photo sequence showing relative changes in density of mesquite between 1903, 1948, and 1988, looking east up Proctor Canyon. Mesquite density changed little on wooded draws compared to upland sites.
- Photo sequence showing differences in range conditions and vegetational changes from grassland (1905) to a more woody type dominated by cactus (1941) to a mesquite savannah (1988). Vegetation species are native grassland species.
- Photo sequence showing differences in range conditions between 1910, 1951, and 1988. In 1910 and 1951, native vegetation was the dominant aspect, whereas in 1988 the understory has become largely a monoculture of lehmann lovegra
ss,
an exotic. Note also the change in woody composition similar to figures 5-7.
- This upland site changed from a native grassland site (1922) with few woody species to a mesquite-cactus-burroweed type (1947), to a mesquite-Lehmann lovegrass-dominated savannah (1988). Note that cactus has completely cycled
thro
ugh and lehmann lovegrass has outcompeted burroweed.
- Photo sequence showing little encroachment by woody plants between 1936, 1959, and 1988. Range condition improved significantly, with native species still dominant in 1959. Pastures of this type are presently classified as mo
nocu
ltures of lehmann lovegrass.
NOTE --THESE FIGURES ARE PART OF APPENDIX D.
