Line intercept data of long-term vegetation responses to shrub removal and lagomorph exclusion in a creosotebush community

The purpose of this study is to quantify vegetation dynamics in
response to lagomorph and shrub exclusion. Data consist of
vertical line intercept measures of the perennial grasses,
suffretescents and shrubs.
Sixteen plots at each of 3 sites (Gravelly Ridges, Dona Ana
exclosure, and Parker Tank) were established in 1938-39 by Ken
Valentine. Plots were 21.3 x 21.3 m in 4 rows of 4 plots with a
7.6 m buffer zone. All plots were sampled before treatments.
Plots were divided into east and west halves and 14 randomly
located 10.65 m transects were located in each half plot.
Vegetation (black grama, dropseeds, bush muhly, fluff grass, other
grasses, creosotebush, honey mesquite, tarbush, mariola, and other
shrubs) was measured using vertical line point intercepts. Plots
have been re-read in 1947, 1956, 1960, 1967, 1989, 1995, and 2001
for Gravelly Ridges and 1939, 1947, 1960, 1967, and 2001 for Dona
Ana and Parker Tank using the same methods. Treatments were
applied factorially yielding a control plot, single factor plots,
and plots with varying degrees of combinations of factors. The
factors were lagomorph exclusion (using wire fencing), shrub
removal (hand grubbing at the ground surface), furrowing (shallow,
hand raked furrows to trap surface water), and seeding (broadcast
applications of seeds of native perennials). Seeding and
furrowing treatments were only applied in 1939. Lagomorph
exclusion has persisted since establishment, and shrub removal
treatments have been reapplied immediately following all years of
vegetation sampling.