Quadrat vegetation cover data on 1m x 1m plots from the long-term Small Mammal Exclusion Study (SMES) at Jornada Basin LTER, 1995-2020

This data package contains vegetation cover from plots with various
levels of herbivore exclusion on the Jornada Experimental Range
(JER) and Chihuahuan Desert Rangeland Research Center (CDRRC) in
Dona Ana County, southern New Mexico, USA. Study sites were
established in 1995; one in black grama grassland and the other in
creosotebush shrubland to compare the impact of herbivores on
ecosystem processes between these vegetation types. Parallel studies
were established at the Sevilleta LTER site (New Mexico, USA) and
Mapimi Biosphere Reserve (Durango, Mexico). Each study site is 1 km
by 0.5 km in area. Four replicate experimental blocks were randomly
located at the grassland study site to measure vegetation responses
using exclusion treatments including a) all mammalian herbivores,
including cattle, lagomorphs, and rodents, b) lagomorphs and cattle
only, c) cattle only, and d) control accessible to all herbivores.
Because grazing cattle are excluded from the entire creosote site,
only three replicate experimental blocks were randomly located there
including a) all mammalian herbivores, including lagomorphs, and
rodents, b) lagomorphs only, and c) control accessible to all
herbivores. Thirty-six sampling points were positioned at 5.8-meter
intervals on a systematically located 6 by 6 point grid within each
plot. A permanent one-meter by one-meter vegetation measurement
quadrat is located at each of the 36 points. At each quadrat,
percent cover by individual plant species is measured. Other
measurements include height (cm) of each species in the quadrat, and
plant condition (living or dead). Data were collected in the spring
and fall of every year from 1995 to 2005. After 2005, sampling
frequency changed to every 5 years in the fall. This study is
ongoing.