Vegetation Classification and Mapping Project Report - USGS

Vegetation Classification and Distribution Mapping Report: Petrified Forest National Park
C.2 Woodland
C.2.2. Pinus edulis - (Juniperus osteosperma) / Bouteloua gracilis Woodland
Base map class
NatureServe common name
NatureServe code
Pinus edulis.-.(Juniperus osteosperma)./.Bouteloua gracilis.
Woodland.was.only.located.at.one.small.area..This.association.
was.mapped.with.the.One-seed.Juniper./.Bigelow’s.Sagebrush.
Shrubland.base.map.class.
Two-needle.Pinyon.-.(Utah.Juniper)./.Blue.Grama.Woodland
CEGL000778
Summary:
This woodland association is known from mountains and mesas in the southern Colorado Plateau,
from the Mogollon Rim, extending north into southern Utah and probably western Colorado.
Elevations normally range from 1700-2400 m (5575-7875 ft). Sites are variable but generally are
relatively dry and rocky. Stands occur on flat to moderate slopes along drainages and on mesatops,
on gentle to moderate (10-40%) rocky slopes of foothills, and at the bases of cinder cones. The
substrates are variable and range from deep, coarse-textured soils derived from cinder to finertextured
soils derived from sandstone, shale and limestone. The vegetation is characterized by an
open to moderately dense tree canopy (10-65% cover) codominated by Pinus edulis and Juniperus
osteosperma trees that are between 1 and 5 m tall. Pinus edulis may be present with relatively
small cover in some stands. Juniperus deppeana may replace Juniperus osteosperma in southern
stands. Other species of Juniperus, such as Juniperus scopulorum, may be present in higher elevation
stands. Shrub cover is sparse (