Name:
Panicum obtusum Grassland
Reference:
NatureServe Biotics 2019
Description:
This herbaceous association is found in New Mexico, Texas, and Colorado. It is described from Lake Meredith National Recreation Area in Texas as well as El Paso, Otero, and Huerfano counties in southeastern Colorado. The composition and structure of this community are influenced by climate, soils (texture, depth, and overflow), slope, natural fire and grazing pressure. It occurs on broad, gently sloping overflow sites along major drainages. The soils are deep, medium- to moderately fine-textured with moderately high fertility. Infiltration is moderately rapid and runoff is moderate. The soils are formed from colluvial deposits and are considered uplands, although overflow can occasionally occur. The productive capacity is greater than the adjoining upland communities due to receiving extra runoff from surrounding upland sites. Natural fire helped to shape the natural plant community and probably occurred every 8 to 10 years in presettlement times. This community is attractive to domestic grazing animals and has been subject to overgrazing in past decades. This grassland is dominated by <i>Panicum obtusum</i>. There are several other species of grass occurring in lesser amounts, including <i>Pascopyrum smithii, Sporobolus compositus var. compositus, Bouteloua curtipendula</i>, and <i>Bothriochloa laguroides</i>. Forbs are variable in composition depending on moisture conditions. The major species include <i>Solanum elaeagnifolium, Ambrosia psilostachya, Centaurea americana, Grindelia papposa, Oenothera cinerea</i>, and <i>Sphaeralcea angustifolia</i>. There are usually few shrubs present. <i>Prosopis glandulosa</i> occurs but is usually sparse. Cacti are rare, although <i>Opuntia phaeacantha</i> and <i>Opuntia macrorhiza</i> are both present. Trees are rare except for occasional <i>Celtis laevigata var. reticulata</i>. The associated graminoid species documented within the Colorado stands include <i>Lycurus phleoides, Sporobolus airoides, Sporobolus cryptandrus, Muhlenbergia asperifolia, Pascopyrum smithii</i>, and <i>Distichlis spicata</i>. Forbs are typically weedy species with low cover, such as <i>Bassia scoparia, Salsola kali, Symphyotrichum falcatum</i>, and <i>Grindelia squarrosa</i>, Shrubs are scant and include <i>Juniperus monosperma, Tamarix chinensis, Elaeagnus angustifolia, Salix amygdaloides, Salix exigua</i>, and occasionally <i>Populus deltoides ssp. monilifera</i> in the tree layer.
Accession Code:
urn:lsid:vegbank.org:commConcept:31616-{8041B1E5-E7E0-4E5E-B542-120FB43F9A67}
Plot-observations of this Community Concept:
0
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