Vegetation Classification and Mapping Project Report - USGS

Appendix E: Plant community and map class key
class.is.distinguished.by.its.landform.characteristic.and.occurs.in.areas.of.intermittent.flooding,.such.as.washes,.along.wash.banks,.and.on.wash.terraces..This.map.class.contains.a.mix.
of.herbaceous.and.shrub.species..No.one.individual.association.was.determined.to.represent.
this.map.class.which.contains.a.complex.of.associations.and.unique.communities..Associations.that.can.occur.in.this.complex.include,.but.are.not.limited.to,.Allenrolfea
occidentalis.
Shrubland,.Calamovilfa gigantea.Desert.Wash.Shrub.Herbaceous.Vegetation,.Ericameria
nauseosa.Desert.Wash.Shrubland,.Ericameria nauseosa./.Bouteloua gracilis.Shrub.Herbaceous.Vegetation,.Isocoma
drummondii./.Pleuraphis jamesii Shrubland,.Salix exigua./.Barren.
Shrubland,.Sarcobatus vermiculatus./.Atriplex obovata.Shrubland,.Sarcobatus vermiculatus./.
Suaeda moquinii.Shrubland,.Suaeda moquinii.Shrubland,.Tamarix.spp..Semi-Natural.Temporarily.Flooded.Shrubland..This.map.class.contains.a.mix.of.species.and.associations.and.was.
defined.as.a.heterogeneous.group.of.associations..
•. Base.map.class:.Vegetated.Wash.Complex
•. Group.map.class:.Inter-Mountain.Basins.Wash
•. Management.map.class:.Vegetated.Wash.Complex
•. Association:.NA
Key C: Woodlands
Trees.are.the.dominant.lifeform..Total.vegetation.cover.is.generally.>10%.cover,.except.in.dry.sites.
where.vegetation.cover.can.be.as.low.as.2%.cover..Trees.dominate.the.woodlands.and.generally.
have.>10%.canopy.cover..If.shrub.cover.is.more.than.tree.cover,.go.to.Key.D:.Shrubs.
29a..
29b...
30a..
30b..
.Juniperus monosperma.dominates.the.tree.species..Juniperus monosperma.is.a.short.tree.
that.tends.to.have.a.tall.shrub-like.appearance.and.occurs.in.low.density..Artemisia bigelovii.typically.occurs.as.an.indicator.species.in.the.understory.of.this.map.class..Occasionally.
Artemisia bigelovii.dominates.the.understory,.but.it.does.not.have.to.occur..The.understory.
typically.consists.of.a.sparse.cover.of.shrub.and.herbaceous.species.
•. Base.map.class:.One-seed.Juniper./.Bigelow’s.Sagebrush.Shrubland
•. Group.map.class:.Colorado.Plateau.Pinyon-Juniper.Woodland
•. Management.map.class:.One-seed.Juniper./.Bigelow’s.Sagebrush.Shrubland
•. Association:.Juniperus monosperma./.Artemisia bigelovii.Woodland
Tree.species.not.as.above..(30a)
.Tree.species.are.dominated.by.Pinus edulis.and/or.Juniperus osteosperma..Both.of.these.tree.
species.occur.in.low.densities..The.understory.tends.to.have.a.low.cover.of.herbaceous.and.
shrub.species..The.herbaceous.cover.often.consists.of.a.low.to.moderate.cover.of.Bouteloua
gracilis..This.map.class.is.restricted.to.the.higher.elevations.of.the.northern.half.of.the.project.boundary..
•. Association:.Pinus edulis.-.(Juniperus osteosperma)./.Bouteloua gracilis.Woodland
.Populus fremontii.is.the.dominant.tree.species..Ericameria nauseosa.commonly.occurs.as.a.
tall.shrub.in.the.understory..This.community.is.restricted.to.areas.with.intermittent.stream.
flow.and.mostly.commonly.occurs.along.the.banks.of.the.Puerco.River.
•. Base.map.class:.Cottonwood./.Rubber.Rabbitbrush.Woodland
•. Group.map.class:.Inter-Mountain.Basins.Riparian.Woodland.and.Shrubland
•. Management.map.class:.Cottonwood./.Rubber.Rabbitbrush.Woodland
•. Association:.Populus fremontii./.Ericameria nauseosa.Woodland
Key D: Shrublands
Shrubs.are.the.dominant.lifeform..Total.vegetation.cover.is.generally.>10%.cover;.in.particularly.dry.
sites.vegetation.cover.can.be.as.low.as.2%.cover..Tree.cover.is.less.than.the.total.shrub.cover.and.