Name:
Bouteloua gracilis - Bouteloua dactyloides Shortgrass Prairie Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This macrogroup forms the matrix grassland in the western half of the Western Great Plains Division east of the Rocky Mountains and ranges from southeastern Wyoming and the western Nebraska panhandle south into the panhandles of Oklahoma and Texas and eastern New Mexico. The vegetation is primarily dominated by <i>Bouteloua gracilis</i> and <i>Bouteloua dactyloides</i> throughout its range, with various associated graminoid species changing depending on latitude, precipitation, soils, and management. In the southern portion <i>Prosopis glandulosa</i> may form a sparse to moderately dense short-tree or shrub canopy in uplands over shortgrass understory. Associated graminoids may include <i>Achnatherum hymenoides, Aristida purpurea, Bouteloua curtipendula, Bouteloua hirsuta, Carex filifolia, Carex inops ssp. heliophila, Eragrostis intermedia, Hesperostipa comata, Hesperostipa neomexicana, Koeleria macrantha, Muhlenbergia torreyi, Pascopyrum smithii, Pleuraphis jamesii, Sporobolus airoides</i>, and <i>Sporobolus cryptandrus</i>. Although mid-height grass species may be present, especially on more mesic land positions and soils, they are secondary in importance to the sod-forming short grasses. Sandy soils have higher cover of <i>Hesperostipa comata, Sporobolus cryptandrus</i>, and <i>Yucca glauca</i>. Scattered shrub and dwarf-shrub species may also be present. <i>Gutierrezia sarothrae</i> is often present to codominant especially in disturbed areas. Cacti species such as cholla (<i>Cylindropuntia imbricata</i>) and prickly-pears (<i>Opuntia polyacantha</i> and <i>Opuntia phaeacantha</i>) can be abundant on some sites. Stands occur on primarily flat to rolling uplands. Soils typically are loamy and ustic but range from sandy to clayey. Climate is temperate, semi-arid continental with mean annual precipitation generally about 300 mm, ranging up to 500 mm in the warmer south extent where precipitation is less effective. Annual precipitation has a bimodal distribution, occurring mostly before the growing season in winter and early spring and then during summer as monsoon thunderstorms. Summer precipitation events are mostly <10 cm but occasionally larger. High variation in amount and timing of annual precipitation impacts the relative cover of cool- and warm-season herbaceous species.<br /><br />Climate, fire and grazing constitute the primary processes impacting this macrogroup. In contrast to other prairie macrogroups, fire is less important, especially in the western range because the dry to xeric climate conditions produce less vegetation/fuel load. However, historically, fires that did occur were often very expansive, especially after a series of years with above-average precipitation when litter/fine fuels can build up. Currently, fire suppression and more extensive grazing in the region have likely decreased the fire frequency, and it is unlikely that these processes could occur at a natural scale. A large part of the range for this macrogroup (especially in the east and near rivers) has been converted to agriculture. Areas of the central and western range have been impacted by the unsuccessful attempts to develop dryland cultivation during the Dust Bowl of the 1930s. Historically, mesquite shrublands probably occurred as a natural component on more fertile soils and along drainages, but they have expanded their range into prairie uplands in recent decades.
Accession Code:
urn:lsid:vegbank.org:commConcept:40473-{8D0FD6D2-C5A3-408F-9146-EC7B52D74BF4}
Plot-observations of this Community Concept:
0
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