Madrean Lower Montane Pine - Oak Forest and Woodland
Geology
Tertiary igneous substrates are commonly encountered with this system in the Davis Mountains region, but the system may also occur on sandstone and limestone substrates, such as in the Guadalupe Mountains region.
Landform
This system occupies the relatively rugged slopes of the mountainous areas of the Trans-Pecos, but may also occupy gently rolling landscapes at higher elevations.
Soils
Often rocky soils derived from igneous and sedimentary substrates, but also mountain loams.
Parent Description
This system occurs at higher elevations of the Davis, Chisos, and Guadalupe Mountains than the Madrean Pinyon – Juniper Woodland. It is typically dominated by Pinus ponderosa (ponderosa pine) [or Pinus arizonica (Arizona pine) in the Chisos], but oak species such as Quercus emoryi (Emory oak), Quercus grisea (gray oak), Quercus x pauciloba (wavyleaf oak), and Quercus gambelii (Gambel oak) may be present to codominant. The subcanopy and shrub layer are typically not dense and may include species of the canopy as well as Quercus hypoleucoides (silverleaf oak), Juniperus deppeana (alligator juniper), Cercocarpus montanus (mountain mahogany), Holodiscus dumosus (rockspirea), Symphoricarpos spp. (snowberries), Nolina spp. (sacahuista), Cylindropuntia imbricata (tree cholla), and Mimosa aculeaticarpa var. biuncifera (catclaw mimosa). Pinus cembroides (Mexican pinyon pine), and in the Guadalupe Mountains, Pinus edulis (pinyon pine), becomes a common component, particularly at the lower elevational limits of this type and in more xeric situations. The herbaceous layer is typically dominated by graminoids including Piptochaetium fimbriatum (pinyon ricegrass), Muhlenbergia emersleyi (bull muhly), Muhlenbergia pauciflora (New Mexican muhly), Bouteloua curtipendula (sideoats grama), Bouteloua gracilis (blue grama), Bouteloua hirsuta (hairy grama), Bothriochloa barbinodis (cane bluestem), Bothriochloa laguroides ssp. torreyana (silver bluestem), Andropogon gerardii (big bluestem), Blepharoneuron tricholepis (pine dropseed), Koeleria macrantha (junegrass), Hesperostipa neomexicana (New Mexico feathergrass), Heteropogon contortus (tanglehead), Muhlenbergia montana (mountain muhly), Muhlenbergia dubia (pine muhly), Muhlenbergia rigida (purple muhly), Eragrostis intermedia (plains lovegrass), Panicum bulbosum (bulb panicum), Schizachyrium cirratum (Texas bluestem), and Schizachyrium scoparium (little bluestem).
Ecological Mapping Systems
Trans-Pecos: Ponderosa/Arizona Pine Woodland
Woodlands dominated by Pinus ponderosa (ponderosa pine), though oaks, junipers, and pinyon pines may be common.
Distribution Map
Photos
Trans-Pecos: Ponderosa/Arizona Pine - Oak Woodland
Woodlands co-dominated by Pinus ponderosa (ponderosa pine) and oak species such as Quercus emoryi (Emory oak), Quercus gambelii (Gambel oak), and Quercus grisea (gray oak).
Distribution Map
Photos
Trans-Pecos: Mountain Evergreen Oak - Pine Shrubland
Shrublands representing young growth of the Pinus ponderosa (ponderosa pine) and Quercus spp. (oak) dominated woodlands. Pinus cembroides (Mexican pinyon pine) and Juniperus deppeana (alligator juniper) may be common components of the shrubland.
Distribution Map
Photos
Trans-Pecos: Mountain Grassland
This savanna represents the open, grassy interstices of the pine woodlands of higher elevations. Mid-height grasses such as Piptochaetium fimbriatum (pinyon ricegrass), Muhlenbergia emersleyi (bull muhly), Muhlenbergia pauciflora (New Mexican muhly), Bouteloua curtipendula (sideoats grama), Heteropogon contortus (tanglehead), Bothriochloa laguroides ssp. torreyana (silver bluestem), and Bouteloua gracilis (blue grama) are common dominants.
Distribution Map
Photos
Public Land Occurrence
- Big Bend National Park: US National Park Service
- Black Gap Wildlife Management Area: Texas Parks & Wildlife Department
- Davis Mountains State Park: Texas Parks & Wildlife Department
- Elephant Mountain Wildlife Management Area: Texas Parks & Wildlife Department
- Guadalupe Mountains National Park: US National Park Service
- Sierra Diablo Wildlife Management Area: Texas Parks & Wildlife Department