|
In August and September of 1998 we collected increment cores
from 30-45 of the oldest trees at each of 3 sites along the western
base of the Bighorn Mountains, WY, and the Pryor Mountains, MT
(table below). Each of these sites is a canyon draining the western
side of the mountains and is near the lower elevational limit
of conifer forest and the upper elevational limit of Utah juniper.
The three sites span about 150 km of the eastern
edge of the Bighorn Basin. The oldest trees sampled are of
a different species at each of the 3 sites, although at least
2 of the 3 species are present at each site. At each site we
found a concentration of mature trees along the upper rim of
the canyon. These trees are apparently protected from fire, harvesting,
and possibly from disturbance by livestock grazing. Most of the
cored trees were live, but a few dead trees were sampled to determine
the potential for extending the chronology by collecting cross
sections of dead trees.
We also sampled a few limber pines at 4 other sites (Alkali
Creek, Webber Canyon, John Dent Ranch, and Copper Mountain). |
