East and west boundary fence plant line intercepts - percent cover for 9 species 1982-1992

BACKGROUND.
In the spring of 1982, as part of the establishment of
the Jornada Long-Term Ecological Research site in southern
New Mexico, a 135 ha portion of a 1500 ha, internally
drained, watershed was exclosed from grazing by domestic
livestock. Prior to exclosure the watershed, as well as the
rest of the Jornada basin, had been moderately to heavily
grazed for the past 100 years. Concurrent with grazing, the
vegetation had undergone a dramatic change from desert
grassland, with an almost continuous cover of C4 perennial
grasses, to isolated patches of the original grassland in a
mosaic with desert shrub dominated plant communities
(Buffington and Herbel, 1965).
The exclosure lies along a northeast facing piedmont
slope at the base of a steep isolated mountain peak, and
covers a variety of component landforms from the foot of the
mountain to the basin floor. This provided the opportunity
to investigate the response of vegetation with respect to
landscape characteristics as well as release from grazing.

This summary data set consists of percent cover of 9 species
from the plant line intercept measurements on either side of the
LTER-I exclosure East and West boundary fence. Data is sorted by
station, species i.d., then line segment. Along the East
Boundary fence, the east side is ungrazed (control) and the west
side is grazed (treatment). Along the West Boundary fence, the
east side is grazed and the west side is ungrazed. Each plant
line transect is divided into 6 5-meter segments. All perennials
were measured at about 5 year intervals as the length of
intercept along a 30-meter line perpendicular to the fence.
Summary data includes only four of the 6 5-meter intervals due to
disturbance along fenceline. Data from the 5-meter segment on
either side of the fence was not included in summarizing the
data. Summary data includes only 9 of the perennial species.