Name:
Juniperus monosperma / Bouteloua curtipendula Woodland
Reference:
Western Ecology Working Group of...
Description:
This woodland association is known to occur in Arizona, Colorado, New Mexico, Oklahoma, and Texas. It occurs on sites with moderate solar exposure, on all aspects of lower hillslopes or on alluvial terraces in or adjacent to canyon bottom floodplains. This association can also occur on steep, colluvial slopes of escarpments, dipslopes of moderate slope, and occasionally on lower toeslopes and valley bottoms. Soils are shallow, gravelly to rocky and are derived from basalt, andesite, or tuff colluvium, or mixed mineralogy alluvium. Slope sites tend to be rocky and gravelly, while terraces are less so, but with significant exposed soil and litter accumulation. Boulders and bedrock may occupy 50% of the site. Soils may also be loamy Inceptisols and Mollisols derived from sedimentary limestone and calcitic sandstone. Elevation ranges from 1500 to 2300 m (5000-7500 feet).<br><br>Within the Bandelier National Monument in north-central New Mexico, this low-statured woodland is characterized by mature <i>Juniperus monosperma</i> trees forming sparse to open canopies (10-35%) with scattered <i>Pinus edulis</i> seedlings or saplings in the subcanopy. Shrubs are poorly represented but may include succulents such as <i>Opuntia</i> spp. Scattered graminoids are found in the inter-tree spaces with <i>Bouteloua curtipendula</i> the most abundant and dominant, with an assortment of other plains grassland species present but not dominant. Within the adjacent Los Alamos region, this is the dominant community type in the juniper savanna. Numerous shrub species may be present with frequencies ranging from 30 to 40%. However, overall shrub coverages are low. The understory vegetation tends to be graminoid; however, the overall grass coverage may be as little as 5%. One or more of <i>Bouteloua curtipendula, Bouteloua eriopoda, Lycurus phleoides</i>, or <i>Pleuraphis jamesii (= Hilaria jamesii)</i> represents up to 50% of the overall grass coverage. <i>Bouteloua gracilis</i> or <i>Bouteloua hirsuta</i> may also be abundant.<br><br>At White Sands Missile Range, this juniper woodland occurs on steep rocky slopes. <i>Juniperus monosperma</i> is the dominant tree in the very open to moderately open tree canopy. <i>Pinus edulis</i> may be present, but it is only an occasional or minor associate. <i>Bouteloua curtipendula</i> is the dominant grass species. <i>Bouteloua gracilis, Bouteloua hirsuta</i>, and <i>Aristida purpurea</i> can be abundant but not dominant; <i>Hesperostipa neomexicana (= Stipa neomexicana)</i> can occur under the tree canopies. The shrub layer is very diverse but is generally under 5% cover. Forb diversity is likewise very high, but forb cover is very low and not consistent in composition from stand to stand. Within Lake Meredith National Recreation Area in Texas, this community is dominated by <i>Juniperus monosperma</i> with an understory of smaller shrubs, grasses and forbs. The amount of juniper in the community has generally increased over the past several decades. More mesic slopes facing east or north grow larger juniper and tend to have more species diversity. The most common grass is <i>Bouteloua curtipendula</i>, which is well-distributed throughout the community.
Accession Code:
VB.CC.33563.CEGL000708
Plot-observations of this Community Concept:
0
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