Percent cover of vegetation measured by the line-intercept method at multiple locations on long-term ecosystem transects (including nitrogen fertilization treatments) at Jornada Basin LTER, 1982-2014

This data package contains data on the average percent cover of plant species on three permanent LTER-I transects at the Chihuahuan Desert Rangeland Research Center (CDRRC) in southern New Mexico. Prior to becoming a livestock exclosure, the study site was moderately to heavily grazed for the past 100 years. The purpose of this study was to document the vegetation changes associated with the addition of nitrogen fertilizer following nearly a century of grazing. Three permanent, parallel transects (2.7 km in length) run from the middle of the College Playa up to the foot of Mt. Summerford. The Treatment transect was treated annually with ammonium nitrate fertilizer (NH4NO3 at 10g N/m2/yr) until 1987. Along each transect, 91 stations, each with a plant intercept line, are spaced at 30 meter intervals. Each plant intercept line is perpendicular to a 2.7 km transect and is 30 meters in length broken into 5 meter segments. The included dataset gives calculated average percent cover of each plant species for each of these plant intercept lines on all three LTER-I permanent transects (91 lines each). Measurements were made biannually from 1982 - 1988. After this, they are measured every 5 years. Data consists of the date, week number, transect, station number, JRN species code, USDA Plants code, species binomial, photosynthetic pathway, habit, form, and average percent cover. This study is ongoing.