Ouachita Mountain Oak Forest

EVT 7312Ouachita Montane Oak Forest
CES202.306GNRTreeHardwood
Summary
This system represents hardwood forests of the highest elevations of the Ouachita, Rich, and Black Fork mountains of Arkansas and Oklahoma (about 790-850 m [2600-2800 feet]). Vegetation consists of either forests or open woodlands dominated by Quercus alba or Quercus stellata. Canopy trees are often stunted due to the effects of ice, wind and cold conditions, in combination with fog, shallow soils over rock, and periodic severe drought. Some stands form almost impenetrable thickets.
Source: NatureServe Explorer
Vegetation
The vegetation of this system consists of either forests or open woodlands dominated by Quercus alba or Quercus stellata. Some examples may have Quercus marilandica var. ashei; herb layers may contain Carex pensylvanica and/or Carex ouachitana. In addition, Quercus rubra, Quercus stellata, Carya texana, and Quercus marilandica may occur as minor components of the canopy. Associated woody species of minor importance include Amelanchier arborea, Acer rubrum var. rubrum, Sassafras albidum, Vaccinium pallidum, Vaccinium stamineum, Rubus spp., Nyssa sylvatica, Hamamelis virginiana, Rhus copallinum, Rhus glabra, Pinus echinata, Chionanthus virginicus, Ulmus alata, Smilax spp., and Rubus spp. The ground layer may have a mosaic of sedge-dominated and lichen/moss-dominated areas. In addition to Carex pensylvanica and Carex ouachitana, herbaceous species include Carex albicans var. albicans, Carex nigromarginata, Deschampsia flexuosa, Schizachyrium scoparium, Elymus spp., Maianthemum racemosum, Hypericum sp., Baptisia sp., Cynoglossum virginianum var. virginianum, Agalinis sp., Dichanthelium spp., Solidago ulmifolia, and Solidago spp.
Source: NatureServe Explorer
Environment
This system is restricted to the highest elevations of the Ouachita, Rich, and Black Fork mountains of Arkansas and Oklahoma (about 790-850 m [2600-2800 feet]). Ecological factors include the effects of ice, wind and cold, in combination with fog, shallow soils over rock, and periodic severe drought.
Source: NatureServe Explorer
Dynamics
Canopy trees are often stunted due to the effects of ice, wind and cold conditions, in combination with fog, shallow soils over rock, and periodic severe drought.
Source: NatureServe Explorer
Distribution
This system is found at the highest elevations of the Ouachita, Rich, and Black Fork mountains of Arkansas and Oklahoma (about 790-850 m [2600-2800 feet]).
Source: NatureServe Explorer
Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Tree canopy

Quercus alba, Quercus marilandica var. ashei, Quercus stellata

Herb (field)

Avenella flexuosa, Carex ouachitana, Carex pensylvanica, Schizachyrium scoparium
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (3)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Mammals (2)

Common NameScientific NameG-Rank
Eastern Gray SquirrelSciurus carolinensisG5
Eastern ChipmunkTamias striatusG5

Amphibians (1)

Common NameScientific NameG-Rank
Ozark Zigzag SalamanderPlethodon angusticlaviusG4
Source: NatureServe Ecological System assessment
Component Associations (3)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

NameG-Rank
Quercus alba / Carex pensylvanica - Carex ouachitana Dwarf WoodlandG1 NatureServe
Quercus alba - Carya tomentosa / Ostrya virginiana / Carex pensylvanica - Schizachyrium scoparium WoodlandG3 NatureServe
Quercus stellata - Quercus marilandica var. ashei Interior Highlands Scrub WoodlandG2 NatureServe
State Conservation Ranks (2)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

StateS-Rank
ARSNR
OKSNR
Roadless Areas (3)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

Arkansas (1)

AreaForestCoverageHectares
Rich Mountain (AR)Ouachita National Forest15.6%162.81

Oklahoma (2)

AreaForestCoverageHectares
Rich Mountain (OK)Ouachita National Forest12.7%257.76
Beech CreekOuachita National Forest1.5%50.94
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.