Physiognomy and Structure: No Data Available

Floristics: This woodland/savanna is characterized by an open canopy of mature Juniperus monosperma trees with scattered saplings or seedlings. Pinus edulis may co-occur as seedlings, saplings, or mature individuals, and Pinus ponderosa is found occasionally. In the shrub layer, Quercus x pauciloba is well-represented in the intercanopy spaces. Additional shrub species may be present, including Atriplex canescens, Cercocarpus montanus var. paucidentatus, Dalea formosa, Ephedra viridis, Fallugia paradoxa, Lycium pallidum, Nolina microcarpa, Opuntia spp., Quercus turbinella, and Yucca spp. In the herbaceous layer, graminoids can be well-represented with dominant species including Bouteloua gracilis along with Bouteloua eriopoda and Schizachyrium scoparium. Additional graminoids may include Bouteloua curtipendula, Elymus elymoides, Eragrostis intermedia, Muhlenbergia spp., and Achnatherum and Hesperostipa spp. (= Stipa spp.). Forbs are scarce.

Dynamics:  Within the Great Plains Province, Juniperus monosperma / Quercus x pauciloba woodlands may occur on prominent escarpments and topographic breaks which serve as refugia from grass fires for formerly widespread woodlands from the late Pleistocene and early Holocene (Naumann 1987 in Stuever and Hayden 1997a). Juniperus monosperma is extremely drought-tolerant. It is also non-sprouting and may be killed by fire (Wright et al. 1979). The effect of fire on a stand is largely dependent on the tree height and density, fine fuel load on the ground, weather conditions, and season (Dwyer and Pieper 1967, Wright et al. 1979). Trees are more vulnerable in open stands where fires frequently occur in the spring, the relative humidity is low, wind speeds are over 10-20 mph, and there is adequate fine fuels to carry fire (Wright et al. 1979, Fischer and Bradley 1987). Under other conditions, burns tend to be spotty with low tree mortality. Large trees are generally not killed unless fine fuels, such as tumbleweeds, have accumulated beneath the tree to provide ladder fuels for the fire to reach the crown. Closed-canopy stands rarely burn because they typically do not have enough understory or wind to carry a fire. Altered fire regimes, cutting trees for fencing, and improper grazing by livestock have significant impacts on the quality of sites. Grazing by livestock can modify the fire regime by removing the fine fuels that carry fire. Juniperus monosperma invasion into grasslands has occurred in places. Control efforts by chaining and prescribed burning have mixed results. More study is needed to understand and manage these woodlands ecologically.