Search for: All records

This dataset contains data on the occurrence of rabbits, birds, and lizards observed along the Jornada Basin LTER (II) animal transects in southern New Mexico, USA. Five, 1 km transects were established, each in a different vegetation zone, near the current NPP study locations C-CALI, G-IBPE, M-NORT, P-COLL, and T-EAST. An observer walked each transect once every two weeks from early 1989 through 1994 recording animals observed along the transects. The data consists of species names, numbers of individuals, and perpendicular distances observed from transects, as well as weather and other context observations. Observation history and species codes are described in additional files. This study is complete. 

This dataset contains long-term precipitation measurements from graduated rain gauges (GRGs) at 21 sites in the Jornada Basin of southern New Mexico, USA. Gauges are located on the Jornada Experimental Range (JER) and the Chihuahuan Desert Rangeland Research Center (CDRRC), and this set of gauges includes all 15 net primary production (NPP) study sites monitored by the Jornada Basin LTER program. At each site a 4 inch diameter cylindrical graduated rain gauge (11" x 0.01" capacity) is mounted on a 4x4 inch diameter redwood post or a wooden exclosure post next to gate at or near each site. For NPP sites, the primary collection is made on the day that monthly hydroprobe soil water content measurements are made. This enables correlation of precipitation with belowground soil water content. Additional data collections during the month may be made in coordination with other studies. Observations at each site come primarily from GRGs. However, at some sites in the NPP study, GRGs were not installed until later, and the nearest available rain gauge in the area has been used to gapfill the precipitation record prior to installation (details in methods section). Rain gauge identity and field measurement date is recorded with each observation in the data file. Other gauge types that may be listed are the Standard Can Gauge (DSRG or dipstick rain gauge), Belfort Weigh Bucket Rain Gauge (WBRG), and Qualimetrics Tipping Bucket Rain Gauge (TBRG). Data collection is ongoing for all 21 gauges in this dataset. 

This data package contains data on lizards sampled by pitfall traps located at 11 consumer plots at Jornada Basin LTER site from 1989-2006. The objective of this study is to observe how shifts in vegetation resulting from desertification processes in the Chihuahaun desert have changed the spatial and temporal availability of resources for consumers. Desertification changes in the Jornada Basin include changes from grass to shrub dominated communities and major soil changes. If grassland systems respond to rainfall without significant lags, but shrub systems do not, then consumer species should reflect these differences. In addition, shifts from grassland to shrubland results in greater structural heterogeneity of the habitats. We hypothesized that consumer populations, diversity, and densities of some consumers will be higher in grasslands than in shrublands and will be related to the NPP of the sites. Lizards were captured in pitfall traps at the 11 LTER II/III consumer plots (a subset of NPP plots) quarterly for 2 weeks per quarter. Variables measured include species, sex, recapture status, snout-vent length, total length, weight, and whether tail is broken or whole. This study is complete. 

This dataset contains long-term precipitation measurements from graduated rain gauges (GRGs) at 21 sites in the Jornada Basin of southern New Mexico, USA. Gauges are located on the Jornada Experimental Range (JER) and the Chihuahuan Desert Rangeland Research Center (CDRRC), and this set of gauges includes all 15 net primary production (NPP) study sites monitored by the Jornada Basin LTER program. At each site a 4 inch diameter cylindrical graduated rain gauge (11" x 0.01" capacity) is mounted on a 4x4 inch diameter redwood post or a wooden exclosure post next to gate at or near each site. For NPP sites, the primary collection is made on the day that monthly hydroprobe soil water content measurements are made. This enables correlation of precipitation with belowground soil water content. Additional data collections during the month may be made in coordination with other studies. Observations at each site come primarily from GRGs. However, at some sites in the NPP study, GRGs were not installed until later, and the nearest available rain gauge in the area has been used to gapfill the precipitation record prior to installation (details in methods section). Rain gauge identity and field measurement date is recorded with each observation in the data file. Other gauge types that may be listed are the Standard Can Gauge (DSRG or dipstick rain gauge), Belfort Weigh Bucket Rain Gauge (WBRG), and Qualimetrics Tipping Bucket Rain Gauge (TBRG). Data collection is ongoing for all 21 gauges in this dataset. 

This data package contains biomass data for annual or perennial grasses and forbs harvested from quadrats along the Jornada Basin LTER (LTER-I) transects in southern New Mexico, USA. These transects are located in a livestock exclosure established in 1982 in the Chihuahuan Desert Rangeland Research Center (CDRRC) and run from the middle of the College Playa up to the foot of Mt. Summerford (2.7 km in length). Prior to the exclosure, the study site was moderately to heavily grazed for the past 100 years. 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 the transect and is 30 meters in length broken into 5-meter segments. The included dataset includes biomass data for grasses and forbs clipped from 1 square meter quadrats directly downslope from some, but not all, of these segments. The harvest measurements occurred in September 1989. Data consists of the date, transect, station number, quad, JRN and USDA Plants species codes, species binomial, habit, form, and biomass. This study is complete. 

This data package contains nitrogen mineralization data from soils collected along the Jornada Basin LTER (LTER-I) transects in southern New Mexico, USA. These transects are located in a livestock exclosure established in 1982 in the Chihuahuan Desert Rangeland Research Center (CDRRC) and run from the middle of the College Playa up to the foot of Mt. Summerford (2.7 km in length). Prior to the exclosure, the study site was moderately to heavily grazed for the past 100 years. 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. For this dataset, 60 soil samples (total) were collected along the control and fertilized treatment transects and mixed with potassium chloride solution (KCl) on Nov 27, 1989, then filter extracted four days later to give a time = 0 incubation value. The dataset contains a soil moisture correction factor, sample weights, total inorganic nitrogen (NO3+NO2-N), and nitrogen in ammonium (NH4-N) for Week 0 of nitrogen mineralization potentials. The soil mineralization data complements the biomass harvest measurements that occurred in September 1989 (dataset knb-lter-jrn.210015001). This study is complete. 

This data package contains nitrogen mineralization data from soils collected along the Jornada Basin LTER (LTER-I) transects in southern New Mexico, USA. These transects are located in a livestock exclosure established in 1982 in the Chihuahuan Desert Rangeland Research Center (CDRRC) and run from the middle of the College Playa up to the foot of Mt. Summerford (2.7 km in length). Prior to the exclosure, the study site was moderately to heavily grazed for the past 100 years. 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. For this dataset, 60 soil samples (total) were collected along the control and fertilized treatment transects and mixed with potassium chloride solution (KCl) on Nov 27, 1989, then filter extracted the following day. The dataset contains a soil moisture correction factor, sample weights, total inorganic nitrogen (NO3+NO2-N), and nitrogen in ammonium (NH4-N) for Week F (field) of nitrogen mineralization potentials. The soil mineralization data complements the biomass harvest measurements that occurred in September 1989 (dataset knb-lter-jrn.210015001). This study is complete.