U.S. Long-Term Ecological Research Network (https://www.lternet.edu)
This dataset quantities vegetation cover at experimental hydrology plots on the New Mexico State University Ranch and USDA Jornada Experimental Range. Plots were located in a zone dominated by creosotebush and a zone dominated by grassland. The goal was to compare nutrient losses between shrublands and grasslands. Plant Cover was measured on 20 2 x 2 m hydrology run off plots using quadrats with 10 x 10 cm units. The number of 10x10cm squares occupied each by plant species was counted and scaled up to determine the total percent cover of each species per plot. Best available judgement was used. For instance, dense grass cover of Bouteloua eriopoda was measured while a thin cover of leaves and stems that may have been present over an area was not. With the annual grasses that were inherently sparse, cover was estimated measuring across the width of the plant. However, the central portion of the bunch grasses were measured as cover and not the scraggly leaf/stem material. Nutrient data can be found in package 210001003. This data collection is complete.
This dataset quantities dissolved nutrients in water surface runoff from natural rainfall events at experimental hydrology plots on the New Mexico State University Ranch and USDA Jornada Experimental Range. Chemical analyses include F, Cl, NO3, SO4 by ion chromatography, NH4 by autoanalyzer, Ca, Mg, Na, K by atomic absorption spectrophotometry, and total N and P by auto- analyzer. Nutrient losses from shrubland plots were greater than from grassland plots. The greater nutrient losses in shrublands were due to higher runoff, rather than higher nutrient concentrations in runoff. This study is complete. Refer to:
Schlesinger, W. H., T. J. Ward, and J. Anderson. 2000. Nutrient losses in runoff from grassland and shrubland habitats in southern New Mexico II: Field plots. Biogeochemistry 49: 69-86.
This grasshopper data was collected from 9 plots on the east bajada of the Dona Ana Mts. Three plots were situated on the bajada parallel to and 200 m south of the LTER transect. Two additional sets of three plots were located 5 km and 10 km south of the LTER transect. Each plot is composed of two 50 m belt transects, each divided into ten 5 m2 quadrats. Grasshoppers were visually sampled in each quadrat/plot, once in May, July and September, in 1983, 1984 and 1985. Each individual grasshopper was recorded, including species, age, sex and substrate where it was found. This study is complete.
This data on annual herbaceous plants was measured on Jornada grasshopper study plots located on the east bajada of the Dona Ana Mts. Three plots were situated on the bajada parallel to and 200m south of the LTER transect. Two additional sets of three plots were located 5km and 10km south of the LTER transect. Each plot was composed of two 50m belt transects, each divided into ten 5m2 quadrats. Annual plants were measured in the NE 1m2 of each quadrat, once in May, July and September in 1983, 1984 and 1985. All individuals of each species were counted and measured. A mean diameter, height, and the total number of individuals/1m2/quadrat were recorded. This study is complete.
OVERVIEW This is the Jornada Long Term Ecological Research site data base for the 2 x 2 meter natural rainfall-runoff plots. There are 4074 plot-events or observations in the data set. Of those 4074 observations, 2745 contained precipitation values greater than zero or contained precipitation values greater than runoff values. Very few observations showed runoff values greater than precipitation. All values are included here for completeness of the data set. These data were collected and analyzed in the laboratory under the supervision of John Anderson (primarily). Dr. Susan M. Bolton and Dr. Tim J. Ward compiled and checked the data. Tim J. Ward is responsible for the final input, checking and presentation of the data set presented below. Questions about the data should be directed to Tim J. Ward through the Jornada LTER.
Soil samples collected 5/12 and 5/13/86 to survey N availability in a variety of grassland and mesquite habitats. Objective is development of hypotheses about desertification processes that degrade grassland into mesquite dominated ecosystems. Measurements made of inorganic soil nitrogen.
Soil samples were collected from mesquite dune site, and analyzed for nutrient content in the plant, N-mineralization potential, rhizobium counts, and microarthropods counts.
Twenty 6 x 6 m plots were established with a 3 m buffer between plots. Five plots were randomly assigned to one of four treatments: (1) chlordane amendment 100ml AI (active ingredients) per 10,000 ml) to exclude microarthropods, (2) sprinkler irrigation (6 mm per week), (3) sprinkler irrigation (6 mm/week) plus chlordate amendment (as above), (4) control (no treatment). Soil total Nitrogen was determined in the rhizosphere of fluffgrass.
A mesocosm experiment was conducted on fluff grass plants to look at the effect of exclusion of mites (with chlordane), nematodes (with NEMACUR), mites and nematodes, on soil available, total and microbial nitrogen. Numbers of microarthropods per 1000g of soil is recorded in this data file.
Twenty 6 x 6 m plots were established with a 3 m buffer between plots. Five plots were randomly assigned to one of four treatments: (1) chlordane amendment 100ml AI (active ingredients) per 10,000 ml) to exclude microarthropods, (2) sprinkler irrigation (6 mm per week), (3) sprinkler irrigation (6 mm/week) plus chlordate amendment (as above), (4) control (no treatment). Measurements are taken on Erioneuron pulchellum at monthly intervals. Three randomly located subsamples are collected from each plot. Data set contains plant diameters, mites soil weight, root weight, nematode soil weight, root total nitrogen, and nematode number.