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{"Abstract":["This dataset includes estimated plant aboveground live biomass data\n measured in 1 m x 1 m quadrats at several sites and experiments\n under the Sevilleta LTER program. Quadrat locations span four\n distinct ecosystems and their ecotones: creosotebush dominated\n Chihuahuan Desert shrubland (est. winter 1999), black\n grama-dominated Chihuahuan Desert grassland (est. winter 1999), blue\n grama-dominated Plains grassland (est. winter 2002), and\n pinon-juniper woodland (est. winter 2003). Data on plant cover and\n height for each plant species are collected per individual plant or\n patch (for clonal plants) within 1 m x 1 m quadrats. These data\n inform population dynamics of foundational and rare plant species.\n Biomass is estimated using plant allometries from non-destructive\n measurements of plant cover and height, and can be used to calculate\n net primary production (NPP), a fundamental ecosystem variable that\n quantifies rates of carbon consumption and fixation. Estimates of\n plant species cover, total plant biomass, or NPP can inform\n understanding of biodiversity, species composition, and energy flow\n at the community scale of biological organization, as well as\n spatial and temporal responses of plants to a range of ecological\n processes and direct experimental manipulations. The cover and\n height of individual plants or patches are sampled twice yearly\n (spring and fall) in permanent 1m x 1m plots within each site or\n experiment. This dataset includes core site monitoring data (CORE,\n GRIDS, ISOWEB, TOWER), observations in response to wildfire (BURN),\n and experimental treatments of extreme drought and delayed monsoon\n rainfall (EDGE), physical disturbance to biological soil crusts on\n the soil surface (CRUST), interannual variability in precipitation\n (MEANVAR), intra-annual variability via additions of monsoon\n rainfall (MRME), additions of nitrogen as ammonium nitrate\n (FERTILIZER), additions of nitrogen x phosphorus x potassium\n (NutNet), and interacting effects of nighttime warming, nitrogen\n addition, and El Niño winter rainfall (WENNDEx). To build allometric\n equations that relate biomass to plant cover or volume, the dataset\n "SEV-LTER quadrat plant cover and height data all sites and\n experiments" is used with a separate dataset of selectively\n harvested plant species "SEV-LTER Plant species mass data for\n allometry." Together, these datasets produced \u201cSEV-LTER quadrat\n plant species biomass all sites and experiments\u201d using the scripts\n posted with the allometry dataset. Data from the CORE sites in this\n dataset were designated as NA-US-011 in the Global Index of\n Vegetation-Plot Databases (GIVD). Data from the TOWER sites in this\n dataset are linked to Ameriflux sites:\n ameriflux.lbl.gov/doi/AmeriFlux/US-Seg and\n ameriflux.lbl.gov/sites/siteinfo/US-Ses."]}
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Soil seedbank analysis under experimental drought and delayed monsoon treatments in blue grama and black grama grassland at Sevilleta
{"Abstract":["This study investigated the question, "Does climate change\n affect vegetation and seed bank composition in desert\n grasslands?" The work was done in the Sevilleta National\n Wildlife Refuge, New Mexico, USA, in in the Extreme Drought in\n Grassland Experiment (EDGE). Vegetation and seed bank species\n composition were recorded in black grama (Bouteloua eriopoda) and\n blue grama (B. gracilis) grasslands at Sevilleta. At each site, two\n rainfall manipulations and ambient controls were established in 2013\n (n=10). Treatments included extreme drought (-66% rainfall\n reduction) and delayed monsoon (precipitation captured during\n July-August and reapplied during September-October). Aboveground\n species composition was assessed and composite soil samples were\n collected in 2017, five years after the experiment started. Seed\n bank composition was evaluated using the seedling emergence method.\n Rainfall treatments increased aboveground species richness at both\n sites, and seed bank richness only in the blue grama community.\n Vegetation cover was reduced by both rainfall manipulations, but\n seed bank density increased or remained the same compared with\n controls. In aboveground vegetation, cover of annual and perennial\n forbs increased, and dominant perennial grasses decreased. In the\n soil seed bank, species composition was similar among all treatments\n and was dominated by annual and perennial forbs. The seed bank was\n more resistant to drought than aboveground vegetation. Because seed\n banks enhance long-term community stability, their drought\n resistance plays an important role in maintaining ecosystem\n processes during and following drought in these grassland\n communities."]}
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- PAR ID:
- 10424099
- Publisher / Repository:
- Environmental Data Initiative
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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{"Abstract":["This dataset includes plant species cover and height data measured\n in 1 m x 1 m quadrats at several sites and experiments under the\n Sevilleta LTER program. Quadrat locations span four distinct\n ecosystems and their ecotones: creosotebush dominated Chihuahuan\n Desert shrubland (est. winter 1999), black grama-dominated\n Chihuahuan Desert grassland (est. winter 1999), blue grama-dominated\n Plains grassland (est. winter 2002), and pinon-juniper woodland\n (est. winter 2003). Data on plant cover and height for each plant\n species are collected per individual plant or patch (for clonal\n plants) within 1 m x 1 m quadrats. These data inform population\n dynamics of foundational and rare plant species. In addition, using\n plant allometries, these non-destructive measurements of plant cover\n and height can be used to calculate net primary production (NPP), a\n fundamental ecosystem variable that quantifies rates of carbon\n consumption and fixation. Estimates of plant species cover, total\n plant biomass, or NPP can inform understanding of biodiversity,\n species composition, and energy flow at the community scale of\n biological organization, as well as spatial and temporal responses\n of plants to a range of ecological processes and direct experimental\n manipulations. The cover and height of individual plants or patches\n are sampled twice yearly (spring and fall) in permanent 1m x 1m\n plots within each site or experiment. This dataset includes core\n site monitoring data (CORE, GRIDS, ISOWEB, TOWER), observations in\n response to wildfire (BURN), and experimental treatments of extreme\n drought and delayed monsoon rainfall (EDGE), physical disturbance to\n biological soil crusts on the soil surface (CRUST), interannual\n variability in precipitation (MEANVAR), intra-annual variability via\n additions of monsoon rainfall (MRME), additions of nitrogen as\n ammonium nitrate (FERTILIZER), additions of nitrogen x phosphorus x\n potassium (NutNet), and interacting effects of nighttime warming,\n nitrogen addition, and El Niño winter rainfall (WENNDEx). To build\n allometric equations that relate biomass to plant cover or volume, a\n separate dataset of selectively harvested plant species is provided\n in "SEV-LTER Plant species mass data for allometry."\n Together, these datasets produce \u201cSEV-LTER Plant biomass all sites\n and experiments\u201d using the scripts posted with that dataset. Data\n from the CORE sites in this dataset were designated as NA-US-011 in\n the Global Index of Vegetation-Plot Databases (GIVD). Data from the\n TOWER sites in this dataset are linked to Ameriflux sites:\n ameriflux.lbl.gov/doi/AmeriFlux/US-Seg and\n ameriflux.lbl.gov/sites/siteinfo/US-Ses."]}more » « less
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Grasshoppers are important animals in semi-arid environments, both as herbivores and as food resources for higher level consumer animals. Grasshoppers tend to be numerous and speciose in semi-arid environments, especially desert grasslands, where they range from environmental specialists to environmental generalists. Grasshopper populations tend to change considerably from year to year, often in response to annual variation in rainfall and plant production. The purpose of this study was to monitor grasshopper species composition and abundance over large temporal and spatial dimentions which include black grama grassland, blue grama grassland, creosotebush shrubland, and pinyon/juniper woodland environments at the Sevilleta, in relation to seasonal and annual variation in precipitation and plant production. Data were collected for all individual species to provide information on community dynamics as well as population dynamics, starting in 1992 and continuing to the present. The working research hypothesis for this study was that grasshopper populations in all environments will correlate positively to seasonal and annual variation in precipitation and plant production. Spring grasshopper populations will be especially high during El Nino years, and late summer populations especially high during La Nina years.more » « less
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Abstract Anthropogenic nutrient enrichment and shifts in herbivory can lead to dramatic changes in the composition and diversity of aboveground plant communities. In turn, this can alter seed banks in the soil, which are cryptic reservoirs of plant diversity. Here, we use data from seven Nutrient Network grassland sites on four continents, encompassing a range of climatic and environmental conditions, to test the joint effects of fertilization and aboveground mammalian herbivory on seed banks and on the similarity between aboveground plant communities and seed banks. We find that fertilization decreases plant species richness and diversity in seed banks, and homogenizes composition between aboveground and seed bank communities. Fertilization increases seed bank abundance especially in the presence of herbivores, while this effect is smaller in the absence of herbivores. Our findings highlight that nutrient enrichment can weaken a diversity maintaining mechanism in grasslands, and that herbivory needs to be considered when assessing nutrient enrichment effects on seed bank abundance.more » « less
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{"Abstract":["Humans are creating significant global environmental change,\n including shifts in climate, increased nitrogen (N) deposition, and\n the facilitation of species invasions. A multi-factorial field\n experiment is being performed in an arid grassland within the\n Sevilleta National Wildlife Refuge (NWR) to simulate increased\n nighttime temperature, higher N deposition, and heightened El Niño\n frequency (which increases winter precipitation by an average of\n 50%). The purpose of the experiment is to better understand the\n potential effects of environmental change on grassland community\n composition and the growth of introduced creosote seeds and\n seedlings. The focus is on the response of three dominant species,\n all of which are near their range margins and thus may be\n particularly susceptible to environmental change. It is hypothesized\n that warmer summer temperatures and increased evaporation will favor\n growth of black grama (Bouteloua eriopoda), a desert grass, but that\n increased winter precipitation and/or available nitrogen will favor\n the growth of blue grama (Bouteloua gracilis), a shortgrass prairie\n species. Furthermore, it is thought that the growth and survival of\n introduced creosote (Larrea tridentata) seeds and seedlings will be\n promoted by heightened winter precipitation, N addition, and warmer\n nighttime temperatures. Treatment effects on limiting resources\n (soil moisture, nitrogen mineralization), species growth\n (photosynthetic rates, creosote shoot elongation), species\n abundance, and net primary production (NPP) are all being measured\n to determine the interactive effects of key global change drivers on\n arid grassland plant community dynamics. To measure above-ground NPP\n (i.e., the change in plant biomass, represented by stems, flowers,\n fruit and foliage, over time), the vegetation variables in this\n dataset, including species composition and the cover and height of\n individuals, are sampled twice yearly (spring and fall) at permanent\n 1m x 1m plots. The data from these plots is used to build\n regressions correlating biomass and volume via weights of select\n harvested species obtained in SEV157, "Net Primary Productivity\n (NPP) Weight Data." This biomass data is included in SEV205,\n "Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx):\n Seasonal Biomass and Seasonal and Annual NPP.""]}more » « less
