completed

Data set status is completed, indicating that data is no longer being collected

Dataset: 

Study number: 

37

Data set ID: 

210379002

Abstract: 

Monthly summary of precipitation and air temperature data collected daily from standard U.S. climatological service instruments located at USDA Jornada Experimental Range Headquarters.

Data sources: 

data_JornadaStudy_379_noaa_weather_station_climate_monthly

LTER Core Area(s): 

Keywords: 

Dataset: 

Study number: 

121

Data set ID: 

210121001

Abstract: 

Arid and semi‐arid ecosystems often exhibit diverse plant growth forms in water‐limited environments, but it is unclear whether resource competition (interference) is actually important in structuring communities. We chose a diverse Chihuahuan desert shrubland to examine the response of the plant community to experimental removals of selected perennial plant species or groups of species. Four treatments involved the removal of all individuals of all species of a single functional group (functional group removals: shrub removal, succulent removal, subshrub removal, perennial grass removal). Three other treatments involved removing species within functional groups. These seven treatments plus a control (no plants removed) were replicated six times each in 25×25 m experimental plots, in summer 1995. Permanent belt transects were surveyed for number and sizes of all vascular plants in spring and fall in 1997, 1999, 2000, and 2001. Those plots from which the dominant shrub, Larrea tridentata, was removed had not recovered in total plant cover or volume by 2001, but cover and volume in all other treatments were similar to those in control plots. Relatively few species demonstrated a positive response to the removal of other species or functional groups. The perennial grass group and forbs were the most responsive; perennial grass cover increased in the shrub removal treatment relative to the control but treatment differences diminished after dry growing seasons in 2000 and 2001. Results over the first five years suggest that either environmental conditions or intrinsic biological characteristics limit the ability of most plant species to respond to the removal of substantial fractions of community biomass and composition in the short term. Such slow response by both dominant and less abundant components of the community has implications for the recovery of semi‐arid systems after human disturbance or other events leading to the reduction of biological diversity. This study is complete.

For more information, see:

Buonopane, M., Huenneke L., and Remmenga, M. 2005. Community reponses to removals of plant functional groups and species from a Chihuahuan Desert shrubland. Oikos 110:67-80.

 

Data sources: 

data_JornadaStudy_121_biodiversity_vegetation_transect

LTER Core Area(s): 

Dataset: 

Study number: 

121

Data set ID: 

210121007

Abstract: 

[John Anderson added the following from info provided by Justin Van Zee and edited by Michelle Buonopane.] Overview: In semiarid ecosystems the diversity of plant functional types ( grasses, shrubs, succulents, and so on) and of species may interact with the severe stresses imposed by the desert environment to influence ecosystem processes. Erosion and transport of surface sediment by wind and water is one process that may be affected by the physical structure of the plant community. The Jornada plant diversity experiment, in which the diversity and structure of the plant community have been manipulated in large (25 m x 25 m) plots, offers the opportunity to examine the relative importance of vegetation characteristics and landscape position in determining rates of sediment movement within the plots. Soil erosion is also an important indicator of relative disturbance effects of the treatment manipulations. Each of the 48 plots of the plant diversity experiment contains 5 pans or trays on the downslope side; these accumulate sediments and plant litter that are moving within the plots (carried by wind or by water). Data have been collected on the amount of sediment accumulated in the pans during rainy and during dry seasons, with material sorted and weighed as fine (< 2 mm diameter) or coarse > 2 mm) mineral sediment, plant litter, or rabbit/jackrabbit pellets. Previous statistical analyses found that the mass of material collected per plot is explained only poorly by the treatment (plant community manipulation) of the plot and by block (a rough indication of location on the slope). Objectives: We will test the relative significance of the following variables in explaining plot-level accumulations of sediment and litter: treatment, block, position on slope (the row, from 1 (top of slope) to 10 (bottom), in which the plot is located), the treatment of the plot immediately upslope from the plot, and indices of plant cover and volume (total and by functional group) from the plot-level sampling of vegetation (using fall 1997 data). In addition, we will test the significance of the following variables in explaining the accumulation of sediment and litter in individual pans within a plot: all variables listed above for the plot, plus indices of the vegetative cover and volume located immediately upslope of the pan (weighted for distance from the pan itself).

Data sources: 

data_JornadaStudy_121_biodiversity_erosion_pan

LTER Core Area(s): 

Dataset: 

Study number: 

121

Data set ID: 

210121006

Abstract: 

Changes in plant composition have the potential to cause disturbances in both structure and function throughout the ecosystem. One element of the ecosystem that can be affected is bird diversity and behavior. Certain species of birds depend more, or entirely, on habitats containing specific functional groups or species of vegetation. Habitat preferences in birds develop because of factors such as availability of food, nesting and perching locations, and cover.  Certain species of birds may be generalists while others use a small variety of plants due to strict habitat requirements. In this study we examine how different growth types of plants affect bird abundance, bird species diversity, and bird activity on the Jornada Basin. The experiment took place on the Biodiversity plots (25m X 25m)at the New Mexico State University Chihuahuan Desert Rangeland Research Center from June through August 1997. The site contained 6 blocks, each containing 8 treatments, including: control, perennial grass removal, reduced Larrea cover, reduced Prosopis cover, shrub removal, only a single dominant species of each growth form remaining, subshrubs removal, and succulents removal. The following data were recorded in each plot: species type, time spent in plot, type of vegetation utilized, presence of a pair or family group, and behavior. Behaviors recorded included perching, singing, calling, foraging on the ground, foraging in the vegetation, nesting , and preening. Birds were observed in each plot for periods of 35 minutes with a 10 minute acclimation period prior to the start of the observation period. The replications were done according to a predetermined schedule which was developed in such a manner so as to reduce sampling error as much as possible. This study is complete.

Data sources: 

data_JornadaStudy_121_biodiversity_bird_survey
Bird Species Codes

LTER Core Area(s): 

Dataset: 

Study number: 

121

Data set ID: 

210121003

Abstract: 

Sum of dry mass removed for each plant growth form from each plot of biodiversity experiment. Amount of plant material removed in initial establishment of plant diversity treatments was recorded for later use as covariate or measure of disturbance. Material was weighed in the field by species, and species-level data are available from Huenneke; however, this file summarizes plant material removed (dry mass) by growth form (shrub, subshrub, perennial grass, succulent) and by total live dry mass. Also provided are mass of dead material collected from plots (same species as live material removed for each treatment) and total dry mass, live plus dead.

Data sources: 

data_JornadaStudy_121_biodiversity_biomass_removal

LTER Core Area(s): 

Dataset: 

Study number: 

121

Data set ID: 

210121004

Abstract: 

Pilot study to examine feasibility of measuring individual species response to competing vegetation removal

Data sources: 

data_JornadaStudy_121_biodiversity_plant_response

LTER Core Area(s): 

Dataset: 

Study number: 

394

Data set ID: 

210394008

Abstract: 

**The objective of the present research was to determine whether there have been changes in the structure and function of the surface (0-20cm) soil system, the zone most affected by litter decomposition, which is associated with the rapid movement of mesquite from historical habitats (arroyo and playa fringe) into recent habitats (grassland and dunes). We hypothesized that the soil biotic communities would be poorly developed in the recent mesquite habitats because of lower soil C and nutrient concentrations. As a result of these differences we predicted lower rates of net N mineralization in the soils from recent mesquite habitats. Data set contains analyses for gravimetric soil moisture, pH, phosphate, total Kjeldahl nitrogen, total phosphorus, NO3-N nitrogen mineralization, total inorganic nitrogen, NH4-N nitrogen mineralization, organic carbon, inorganic carbon, total roots, tap roots, intermediate roots, and fine roots.

Data sources: 

data_JornadaStudy_394_mesquite_surface_soil_nutrient

LTER Core Area(s): 

Dataset: 

Study number: 

15

Data set ID: 

210015002

Abstract: 

In the spring of 1982, as part of the establishment of the Jornada Long-Term Ecological Research site in southern New Mexico, a 135 ha portion of a 1500 ha, internally drained, watershed was exclosed from grazing by domestic livestock. Prior to exclosure the watershed, as well as the rest of the Jornada basin, had been moderately to heavily grazed for the past 100 years. Concurrent with grazing, the vegetation had undergone a dramatic change from desert grassland, with an almost continuous cover of C4 perennial grasses, to isolated patches of the original grassland in a mosaic with desert shrub dominated plant communities (Buffington and Herbel, 1965). Three parallel transects (2.7 km in length) run from the middle of the College Playa up into the foot of Mt. Summerford. The Control transect is to the west, the Treatment transect on the east side of the Control transect, and the Alternate Control to the east of the Treatment transect. Each transect is 30 meters wide with a 45 meter buffer zone between each transect. The Treatment transect was treated annually until 1987 with NHNO3 in a concentration equal to 10g N/m2.Soil mineralization was examined on the control and fertilized treatment transects in association with the vegetation biomass study. In 1989, soil properties were measured. This dataset contains soil moisture correction factor, sample weight, total inorganic nitrogen (NO3+NO2-N), and nitrogen in ammonium (NH4-N) for Week F (field) of nitrogen mineralization potentials. This study is complete.

Data sources: 

data_JornadaStudy_015_transect_biomass_soil_mineralization_potential_field

LTER Core Area(s): 

Dataset: 

Study number: 

15

Data set ID: 

210015003

Abstract: 

In the spring of 1982, as part of the establishment of the Jornada Long-Term Ecological Research site in southern New Mexico, a 135 ha portion of a 1500 ha, internally drained, watershed was exclosed from grazing by domestic livestock. Prior to exclosure the watershed, as well as the rest of the Jornada basin, had been moderately to heavily grazed for the past 100 years. Concurrent with grazing, the vegetation had undergone a dramatic change from desert grassland, with an almost continuous cover of C4 perennial grasses, to isolated patches of the original grassland in a mosaic with desert shrub dominated plant communities (Buffington and Herbel, 1965). Three parallel transects (2.7 km in length) run from the middle of the College Playa up into the foot of Mt. Summerford. The Control transect is to the west, the Treatment transect on the east side of the Control transect, and the Alternate Control to the east of the Treatment transect. Each transect is 30 meters wide with a 45 meter buffer zone between each transect. The Treatment transect was treated annually until 1987 with NHNO3 in a concentration equal to 10g N/m2.Soil mineralization was examined on the control and fertilized treatment transects in association with the vegetation biomass study. In 1989, soil properties were measured. This Dataset contains soil moisture correction factor, sample weight, total inorganic nitrogen (NO3+NO2-N), and nitrogen in ammonium (NH4-N) for Week 0 of nitrogen mineralization potentials. This sampling is complete.

Data sources: 

data_JornadaStudy_015_transect_biomass_soil_mineralization_potential_initial_data

LTER Core Area(s): 

Dataset: 

Study number: 

15

Data set ID: 

210015001

Abstract: 

In the spring of 1982, as part of the establishment of the Jornada Long-Term Ecological Research site in southern New Mexico, a 135 ha portion of a 1500 ha, internally drained, watershed was exclosed from grazing by domestic livestock. Prior to exclosure the watershed, as well as the rest of the Jornada basin, had been moderately to heavily grazed for the past 100 years. Concurrent with grazing, the vegetation had undergone a dramatic change from desert grassland, with an almost continuous cover of C4 perennial grasses, to isolated patches of the original grassland in a mosaic with desert shrub dominated plant communities (Buffington and Herbel, 1965).  Three parallel transects (2.7 km in length) run from the middle of the College Playa up into the foot of Mt. Summerford. The Control transect is to the west, the Treatment transect is to the east side of the Control transect, and the Alternate Control is to the east of the Treatment transect. Each transect is 30 meters wide with a 45 meter buffer zone between each transect. The Treatment transect was treated annually until 1987 with NHNO3 in a concentration equal to 10g N/m2. The station markers occur at 30 meter intervals along each transect. Perpendicular to each transect and crossing at each station marker is the 30 meter plant line intercept transect. Biomass of annual and perennial forbs and grasses was obtained from a one meter quad selected at random just downslope from each of  6 5-meter segments of the 30 meter plant line transect located perpendicular to the transect station marker. Data presented here is for the control and treatment transects. This study is complete.

Data sources: 

data_JornadaStudy_015_transect_vegetation_biomass_data

LTER Core Area(s): 

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