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 represented by many species in semi-arid environments, especially in desert grasslands. Grasshopper species 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 a period of many years from 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. 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. This study was initiated in 1992, and is ongoing to the present time.
Physical Dimensions of Sampling Area: 50-meter by one-meter strip transects, between 6, alternating end-points of rodent trap lines on each of 5 rodent trapping webs at each of the 4 sites.
Plot size: Each trapping web is 200-meters diameter, each grasshopper count strip is 50-meters long, by one-meter wide.
Transect Length: 50-meters.
A sample unit consists of 50 by 1-meter strip transect; 6 strip transects per web, 5 webs per site.
Frequency of Sampling
Samples are collected twice each year, early summer and late summer.
Sample size consists of 50-meter by one-meter strip transects.
Visual counts of all grasshoppers on each strip transect. The observer slowly walks each transect, flushing grasshoppers ahead with a one-meter long - inch white PVC pipe. The observer records data on to a voice-activated micro-cassette recorder. Information recorded includes for each individual grasshopper: species, geneder, age class, and the substrate from which the grasshopper was flushed.
Additional Study Area Information
Study Area 1
Study Area Name: Goat Draw (Cerro Montosa)
Site Location Description: Cerro Montosa draw, at north base of Cerro Montosa, Sierra Los Pinos.
Soil: rocky loam.Slope/Aspect: variable steep slopes, all aspects. Vegetation Community: pinyon/juniper woodland, blue grama understory.Terrain/Physiography: rough, dissected erosional montane hills, slopes, and drainages.Geology/Lithology: variable, rhyolite. Hydrology - surface/groundwater: extensive steep arroyo drainages.Size: approximately 1 by 3 km.History (if known): grazed by cattle until 1973.Elevation: approximately 2,000 meters.Climate (general): semi-arid montane, summer rain.
Study Area 2
Study Area Name: Five Points Creosotebush.
Site Location Description: approximately 2km west of Five Points, McKenzie Flats. Soil: sandy loam.Slope/Aspect: slight north-facing slope.Vegetation Community: Chihuahuan Desert creosotebush/black grama grass.Terrain/Physiography: top of Palo Duro Canyon escarpment to south, gentle slope to north. Geology/Lithology: alluvial outwash, extensive caliche near surface.Hydrology - surface/groundwater: slight drainage to the north.Size: approximately 1 by 2 km.History (if known): intensively grazed by cattle until 1973. Elevation: approximately 1,600 meters.Climate (general): semi-arid, summer rain.
Study Area 3
Study Area Name: Five Points Grass.
Site Location Description: approximately 2km NW of Five Points, McKenzie Flats. Soil: sandy loam.Slope/Aspect: gentle rolling terrain.Vegetation Community: black grama grassland.Terrain/Physiography: gentle rolling terrain.Geology/Lithology: alluvial outwash, limestone and caliche.Hydrology - surface/groundwater: slight drainage to the west.Size: approximately 2 by 2 km.History (if known): intensivey grazed by cattle until 1973. Elevation: approximately 1,600 meters. Climate (general): semi-arid, summer rain.
Additional Information on the Data Collection Period
Data are collected in the early summer (April/May) and late summer (September/October).
SEVILLETA LTER CORE SITE GRASSHOPPERSGrasshopper Species ListUpdated: 01/19/00
CODE, FRM L-H, LATIN NAME
ACPI, G, U, Acantherus piperatusAGDE, GT, U, Ageneotettix deorumAMCOG, U, Amphitornus coloradusARCO, T, P, Arphia conspersaARPS, T, U, Arphia pseudonietanaAUEL, GT, U, Aulocara elliottiAUFE, GT, U, Aulocara femoratumBOAR, A, U, Bootettix argentatusBRMA, GT, U, Brachystola magnaCIPA, T, P, Cibolacris parvicepsCOCR, GT, U, Cordillacris crenulataCOOC, GT, U, Cordillacris occipitalisCOTE, T, U, Conozoa texanaDABI, GT, U, Dactylotum bicolorERSI, G, U, Eritettix simplexHATR, T, U, Hadtrotettix trifasciatusHERU, T, U, Heliaula rufaHEVI, A, U, Hesperotettix viridisHICA, T, U, Hippopedon capitoLAAZ, T, U, Lactista aztecaLEWH, T, U, Leprus wheeleriMEAR, A, U, Melanoplus aridusMEAZ, GT, U, Melanoplus arizonaeMEBO, A, U, Melanoplus bowditchiMEGL, GT, U, Melanoplus gladstoniMELA, GT, U, Melanoplus lakinusMEOC, GT, U, Melanoplus occidentalisMETE, G, U, Mermeria texanaOPOB, G, U, Opeia obscuraPAPA, G, U, Paropomala pallidaPHQU, GT, U, Phlibostroma quadrimaculatumPHRO, T, P, Phrynotettix robustusPSDE, GT, P, Psoloessa delicatulaPSTE, GT, P, Psoloessa texanaSCNI, A, U, Schistocerca nitensSYMO, G, U, Syrbula montezumaTRCA, T, U, Trimerotropis californicusTRFO, H, U, Tropidolophus formosusTRKI, T, U, Trachyrhachis kiowaTRPA, T, U, Trimerotropis pallidipennisTRPI, T, U, Trimerotropis pistrinariaXACO, T, P, Xanthippus corallipesXAMO, T, P, Xanthippus montanus