Plant Association Group and Special Habitat Descriptions
Deschutes and Ochoco National Forests, Crooked River National Grassland
Prepared by Katie Grenier, Mike Simpson, Reid Schuller, and Robin Vora
September 2010
Background
Trees, shrubs and other plant life can be classified in many different ways and for many different
purposes. Two classification systems that are commonly used by forest managers to assess
vegetation patterns and their changes over time are “Plant Association Groups” (hereafter PAGs)
and “Special Habitats.” PAGs are mapped on the Deschutes and Ochoco National Forest in the
corporate Geographic Information System (GIS) database.
Each PAG is comprised of five to ten closely related plant associations, or groupings of plants
that occur together in similar environments. These environments are typically defined by their
climates (temperature and moisture), soils, and history of natural disturbances, such as wildfires,
diseases and insect outbreaks. Plant associations vary from tens to hundreds of acres in size.
PAGs typically occur over hundreds to thousands of acres. Thus, PAGS provide a general
picture of major vegetation patterns across a forest. PAGS may also be characterized by features
other than vegetation, such as cinder, glacier, lava, meadow, rock and water. Together, the PAGs
provide a picture of both the vegetation and the non-vegetative features within a large area like a
National Forest.
Special habitats represent features which occupy less than an acre up to tens of acres. These
habitats are often overlooked when examining PAGs, but are important because they support
unusual plant life or contain high biological diversity. For example, non-forest and riparian
habitats are often treated as special habitats because they have a disproportionate value in
conserving biological diversity (USDA Forest Service 1996), although they occupy only a small
proportion of the land base. Similarly, special habitats often support rare plants, mosses, lichens
or fungi.
A brief description of the PAGs occurring on the Deschutes National Forest and the Ochoco
National Forest (including the Crooked River National Grassland) is provided below. This is
followed by a description of the Special Habitats occurring on both National Forests.
Contents
Deschutes National Forest - PAGs .................................................................................................. 2
Ochoco National Forest - PAGs ...................................................................................................... 6
Crooked River National Grassland – PAGs .................................................................................... 8
Special Habitats – Deschutes NF, Ochoco NF ................................................................................ 9
Acknowledgement ........................................................................................................................ 10
References ..................................................................................................................................... 10
Appendix 1. Common and scientific names ..................................................................................11
Page 1 of 11
Deschutes National Forest - PAGs
The PAGs mapped on the Deschutes National Forest reflect a broad range of biophysical
environments, from the alpine peaks of the Three Sisters which receive 145 inches of annual
precipitation, to the juniper woodlands near Bend which averages 12 inches of annual
precipitation. Vegetation on the Forests and Grassland varies with elevation and moisture
gradients from west to east. On the Deschutes National Forest, elevation, precipitation, and
distance from the crest of the Cascade Mountains greatly influence vegetation patterns. These
patterns are also influenced by soils from relatively recent volcanic ash and pumice that are
excessively well drained and cooler than adjacent areas (Simpson 2007).
Table 1 lists the PAGs that are currently mapped on the Deschutes National Forest, and provides
the acres and percentage of the total for each PAG. Many of the plant associations grouped to
form PAGS are those described in Volland (1985). Since this mapping occurred, a new plant
association guide has been completed (Simpson 2007); however, this information is not yet
available in the corporate GIS (Geographic Information System) of the Forest Service. This
report will be updated when that spatial data becomes available.
Table 1. Total acres of mapped Plant Association Groups (PAGs) and their relative percentages
occurring on the Deschutes National Forest.
PAG Name
Alpine Dry
Alpine Meadow
Alpine shrub
Cinder
Glacier
Hardwood
Juniper Woodlands
Lava
Lodgepole Pine Dry
Lodgepole Pine Wet
Meadow
Mesic Shrub
Mixed Conifer Dry
Mixed Conifer Wet
Mountain Hemlock Dry
Ponderosa Pine Dry
Ponderosa Pine Moist
Riparian
Rock
Water
Whitebark Pine Dry
Xeric Shrublands
Deschutes NF
Acres
506
3,732
184
6,972
937
494
2,911
27,514
496,991
70,352
7,678
10,430
304,180
94,565
191,496
574,852
75,787
8,890
12,886
35,695
145
28,227
Deschutes NF
% of Total
0.03
0.2
0.01
0.4
0.05
0.03
0.1
1.4
25
3.6
0.4
0.5
16
5
10
29
4
0.5
1
2
0.01
1
Page 2 of 11
Alpine Dry PAG –Comprising only 0.03% of the mapped PAGS, this type is characterized by
high elevation lodgepole pine and whitebark pine. These stands occur on deep ash/pumice
deposits that are excessively well-drained. Understory vegetation cover and species diversity are
typically low. Herbaceous and shrub fuels are scattered, and litter fuels are scarce. This scarcity
results in a natural fire barrier except under extreme fire weather conditions.
Alpine Meadow PAG – These non-forest plant associations are dominated by sedges, grasses
and forbs occurring at higher elevations in the Cascade Mountains. Soils are imperfectly drained
early in the growing season, often remaining moist well into summer.
Alpine Shrub PAG – These shrub-dominated plant associations occur at high elevations in the
Cascade Mountains. Soils are either imperfectly-drained early in growing season or welldrained. Pink mountain heath (Phyllodoce empetriformis) is a characteristic species.
Hardwood PAG – The hardwoods are dominated by broadleaf, deciduous trees and tall shrubs
including quaking aspen (Populus tremuloides), cottonwood (Populus trichocarpa), mountain
alder (Alnus incana), red osier dogwood (Cornus sericeus), and Engelmann spruce (Picea
engelmanii) which occurs in cold air basins. Common snowberry (Symphoricarpos albus) is a
conspicuous mid-sized shrub.
Juniper Woodlands PAG – Western juniper (Juniperus occidentalis) PAGs occur at low
elevations in the warmest and driest areas within the Forest. Antelope bitterbrush (Purshia
tridentata), Idaho fescue (Festuca idahoensis) and bluebunch wheatgrass (Pseudoroegneria
spicata), and Sandberg bluegrass (Poa secunda) are typical understory species. On the
Deschutes National Forest, the Juniper Woodland PAG is only 0.1% of the total mapped PAG
acres (Table 1). Downed, dead woody fuel loads are often light. Large downed fuels commonly
accounts for 70 percent or more of the total downed woody fuel load. Stands are characterized
by discontinuous patches of needle mat layers. The most abundant surface fuel is curing grass or
shrubs such as bitterbrush, or sagebrush on more productive sites (Simpson et al. 1994).
Occurrence of fire has been reported to be reduced since about 1900 by fire suppression,
reduction of understory fuels by domestic grazing, and construction of roads which act as fire
breaks (Burkhardt 1969), except for some areas that have never sustained frequent fires and have
been occupied by junipers for centuries (e.g., Horse Ridge).
Lodgepole Pine forests – In central Oregon, distribution of lodgepole Pine (Pinus contorta) is
linked directly to ash/pumice deposits, mostly from Mt. Mazama (Simpson 2007). Lodgepole
pine has the widest ecologic variation of all the conifers that occur in central Oregon. It often
occupies areas that are either too wet or too dry for other conifers such as ponderosa pine (Pinus
ponderosa), white fir (Abies concolor), grand fir (Abies grandis), Shasta red fir (Abies magnifica
var. shastensis), or mountain hemlock (Tsuga mertensiana). These PAGs have a mixed severity
fire regime, with a combination of low to high severity fires occurring across the Forest
(Simpson 2007). Average fire return intervals have been reported from 47 to 63 years in the
southern Oregon Cascades, and 60 to 350 years on the Fremont National Forest (Simpson 2007).
The Deschutes National Forest has two lodgepole pine PAGs:
Lodgepole Pine Dry PAG – Typical understory species may include pinemat manzanita
(Arctostaphylos nevadensis), long-stolon sedge (Carex inops), Idaho fescue, and western
needlegrass (Achnatherum occidentale). The scarcity of fine surface fuel limits the
spread of fire except under extreme fire conditions (Agee 1993).
Page 3 of 11
Lodgepole Pine Wetland PAG – Typical species may include western bog blueberry
(Vaccinium occidentale), Douglas’ spirea (Spiraea douglasii), widefruit sedge (Carex
eurycarpa), kinnikinnick (Arctostaphylos uva-ursi), and few-flowered spikerush
(Eleocharis pauciflora). These sites are located within forested floodplains, margins of
wet meadows, and shallow concave sub-irrigated drainages. Water tables are at, or
above, the soil surface through the early and mid-season parts of the growing season
(Simpson 2007). Fires are not limited by surface fuels in this PAG.
Meadow PAG – Meadows are dominated by grasses, sedges, rushes, or forbs (USDA Forest
Service 1988). Soils are either imperfectly-drained or saturated through most of the growing
season. They are often intermixed with riparian areas.
Mesic Shrub PAG – This area is dominated by moisture-loving plants. Willows (Salix spp.),
mountain alder (Alnus incana), western bog blueberry, and Douglas spirea are typical shrubs.
Aquatic sedge (Carex aquatilis), Sitka sedge (Carex sitchensis), beaked sedge (Carex utriculata),
and tufted hairgrass (Deschampsia cespitosa) typically occur.
Mixed conifer forests -These are comprised of a mix of forest species that may include white fir,
Douglas-fir (Pseudotsuga menziesii), mountain hemlock and lodgepole pine. Western white
pine, western larch (Larix occidentalis), and incense cedar (Calocedrus decurrens) may also
occur. Ponderosa pine occurs throughout the mixed conifer PAG, and often is the dominant
species at lower elevations along with white fir, sugar pine (Pinus lambertiana), and lodgepole
pine. Two PAGs are included:
Mixed Conifer Dry PAG – These PAGs have moderate to high productivity and a mean
annual precipitation of 20 to 35 inches. Tree species consist of firs, ponderosa pine,
Douglas-fir, larch, incense cedar, and lodgepole pine. This PAG occupies warm or cold
dry environments. Soil moisture is low due to the occurrence of excessively drained
soils. This PAG is associated with historically very frequent, low-intensity fires.
Evidence from the Klamath-Siskiyou Mountains suggests that small, stand-replacing fires
were not uncommon, but the most common fire type is a low severity underburn
(Simpson 2007).
Mixed Conifer Wet PAG – Plant associations in this PAG have a higher productivity
than the Mixed Conifer Dry PAG and a mean annual precipitation of 35 to 75 inches.
This PAG typically has herb-rich understory vegetation. Shrubs are highly variable but
may include Cascade Oregongrape (Berberis nervosa), golden chinquapin (Chrysolepis
chrysophylla), common prince’s pine (Chimaphila umbellate), dwarf rose (Rosa
gymnocarpa), California blackberry (Rubus ursinus), and creeping snowberry
(Symphoricarpos mollis). Douglas-fir is typically a significant component of overstory
canopies. This PAG has the longest fire return interval and greater incidence of stand
replacing fire within the mixed conifer forest. It is uncertain how fire exclusion has
affected this PAG (Simpson 2007).
Mountain Hemlock Dry PAG –This type, which occurs between 6000-7500’ elevation, ranges
from dense, closed canopy stands of pure mountain hemlock to stands with several dominant tree
species including Pacific silver fir (Abies amabilis) and lodgepole pine along with mountain
hemlock. This PAG represents the cold, dry environments where effective soil moisture is low
Page 4 of 11
and understory species diversity is low. Typical species include smooth woodrush (Luzula
hitchcockii), grouse huckleberry (Vaccinium scoparium), big huckleberry (Vaccinium
membranaceum), and beargrass (Xerophyllum tenax). Lodgepole pine is common after
disturbance. Tree ages are usually old, suggesting that fire frequency is generally low. Wind and
snow loading may be more important disturbance agents than fire. Upper slope and ridgetop
locations favor lightning strikes, but fire spread is limited by moist fuels and the high incidence
of precipitation along with fire strikes (Simpson 2007)
Ponderosa pine forests are widely distributed on the lower east slope of the Oregon Cascades.
Since ponderosa pine occupies drier sites than any other forest type except western juniper or
occasionally lodgepole pine, its distribution is tied closely to available soil moisture. These PAGs
represent the classic low-intensity, high-frequency fire regime that has been the most heavily
impacted by fire suppression. This has resulted in in-filling by young trees and increased
dominance of shrubs and concurrent loss of herbaceous species, as well as environmental
changes such as increased duff depths, buildup of bark flakes and needles at tree bases. Fire
suppression has contributed to development of more homogeneous stands which are more prone
to stand-replacing fires (Hessburg et al. 2004). Where site restoration is the management goal,
prescribed burning, used in combination with thinning and slash removal can be effective
management techniques (Simpson 2007). Two PAGs are included:
Ponderosa Pine Dry PAG – Twenty-nine percent of the Deschutes NF is mapped as
belonging to this PAG. Typical species include antelope bitterbrush, Idaho fescue,
western needlegrass, greenleaf manzanita (Arctostaphylos patula), and snowbrush
(Ceanothus velutinous). This PAG occurs in zones that typically receive less than 20
inches of precipitation.
Ponderosa Pine Moist PAG – Four percent of the PAGS on the Deschutes National
Forest are mapped as this type. Average tree cover of 40-50% occurs in various mixtures
of ponderosa pine and lodgepole pine. Quaking aspen may also be locally abundant.
Shrub cover averages 20% and shrub layers lack diversity. Typical shrubs include
antelope bitterbrush, greenleaf manzanita, kinnikinnick, bearberry (Arctostaphylos
nevadensis), and wax currant (Ribes cereum).
Riparian PAG – Riparian zones occur along the interface between aquatic and terrestrial
ecosystems (Kovalichik 1987). Although great variation exists from high to low elevations,
typical species include: willows, mountain alder, western bog blueberry, and Douglas spirea.
Whitebark Pine PAG – Whitebark pine grows at the highest elevations in Oregon of any
western tree species. Found on exposed ridges, temperatures are cool and the growing season is
short. Winters are long, snowy and frequently involve severe windstorms. While the probability
of increased lightning strikes increases on upper slopes and exposed ridges, late-lying snowpack,
late persistence of moist fuels, and co-occurrence of rain along with lightning combine to limit
the spread of many ignitions, except in prolonged drought periods.
Xeric Shrublands PAG – These plant associations are dominated by big sagebrush (Artemisia
tridentata) and antelope bitterbrush. Soils are well-drained throughout the growing season
(USDA Forest Service 1988). Other typical species include Idaho fescue, bluebunch wheatgrass,
and bottlebrush squirreltail (Elymus elymoides). Trees are absent or sparse. Surface fuels
comprise the majority of the fuel bed.
Page 5 of 11
Ochoco National Forest - PAGs
Table 2 provides data on the 9 Plant Association Groups (PAGs) found on the Ochoco NF. The following
general descriptions of each PAG are from Simpson et al. (1994) and his subsequent work.
Table 2. Total acres of mapped Plant Association Groups (PAGs) and their relative percentages occurring
on the Ochoco National Forest.
PAG
Douglas Fir
Dry Grand Fir
Dry Ponderosa Pine
Juniper Steppe
Juniper Woodland
Mesic Ponderosa Pine
Moist Grand Fir
Shrubland
Subalpine Fir
Ochoco
Acres
95,339
193,801
42,604
22,358
29,261
67,417
63,412
93,377
3,862
Ochoco
% of Total
16
32
7
4
5
11
10
15
0.6
Douglas-Fir PAG – The Douglas-Fir PAG occurs at an average of 4,800 ft. elevation and aspect is
generally south. It includes warm, dry Douglas-fir habitats types where ponderosa pine occurs as a major
seral or climax associate. Many stands have a shrub-dominated undergrowth that may include common
snowberry (Symphoricarpos albus), chokecherry (Prunus virginiana), antelope bitterbrush (Purshia
tridentata), tall Oregongrape (Berberis repens), serviceberry (Amelanchier alnifolia), willow (Salix sp.),
and/or mountain snowberry (Symphoricarpos oreophilus). Elk sedge (Carex geyeri) and pinegrass
(Calamagrostis rubescens) dominate the herbaceous understory in many areas. Fuel loads are
intermediate between the Ponderosa pine PAG and the Dry Grand fir PAG. Fuel loads tend to increase
with stand age as a result of accumulated downfall from insect and disease damage, blowdown, and
natural thinning. Live fuels can be a significant factor, especially where dense thickets of Douglas-fir
develop during fire-free periods (Simpson et al. 1994).
Dry Grand Fir PAG – The Dry Grand Fir PAG includes the most widely distributed and abundant plant
associations on the Ochoco National Forest. Two plant associations make up this group: grand
fir/pinegrass (Abies grandis/Calamagrostis rubescens) and grand fir/elk sedge (Abies grandis/Carex
geyeri). These typically occur on south-facing slopes between 4,000-6,500 ft. elevations. Live fuels in
the form of understory Douglas-fir and ponderosa pine can add greatly to the crown fire hazard,
especially under severe burning conditions. Historically, relatively frequent surface fires maintained open
stands dominated by fire-tolerant ponderosa pine and some Douglas-fir.
Dry Ponderosa Pine PAG – This PAG is found mostly at lower elevations. As moisture increases at
higher elevations in the Forest, the PAG occurs on shallow soils. Typical understory species are
bluebunch wheatgrass (Pseudoroegneria spicata), Idaho fescue (Festuca idahoensis), big sagebrush
(Artemisia tridentata), antelope bitterbrush, curlleaf mountain mahogany (Cercocarpus ledifolius),
western needlegrass (Achnatherum occidentale), and arrowleaf balsamroot (Balsamorhiza sagittata).
Downed, dead woody fuel loads are often light, but still contribute 70 percent or more to the woody fuel
load. Stands are characterized by discontinuous patches of deep to very deep needle mat layers. The
most abundant surface fuel is dead, or curing grass. Dwarf mistletoe adds considerably to fuel loadings in
infested stands (Simpson et al. 2001). Before 1900, fire was a frequent event in ponderosa pine stands
adjacent to western grasslands, occurring at intervals between 5 and 25 years. The natural role of fire in
this PAG is threefold: (1) to maintain grasslands without western juniper or ponderosa pine; (2) to
Page 6 of 11
maintain open stands (parklands) and remove dense understories of saplings, pole-sized trees, or (3) to
thin overstory trees (Simpson et al. 1994).
Juniper Steppe and Juniper Woodland PAGs – Western juniper (Juniperus occidentalis) PAGs occur at
low elevations in the warmest and driest parts of the Forest (Simpson et al. 1994). Big sagebrush
(Artemesia tridentata), Antelope bitterbrush, Idaho fescue and bluebunch wheatgrass are typical
understory species. Downed, dead woody fuel loads are often light. Large downed fuels commonly
accounts for 70 percent or more of the total downed woody fuel load. Stands are characterized by
discontinuous patches of needle mat layers. The most abundant surface fuel is curing grass or shrubs such
as bitterbrush, or sagebrush on more productive sites (Simpson et al. 1994). Occurrence of fire has been
reported to be reduced since about 1900 by fire suppression, reduction of understory fuels by domestic
grazing, and construction of roads which act as fire breaks (Burkhardt 1969), except for some areas that
have never sustained frequent fires and have been occupied by junipers for centuries.
The two PAGS differ primarily in the abundance of western juniper trees present and in soils. The
Juniper Steppe PAG occurs on shallow soils. These sites are much less productive than the Juniper
Woodland PAG sites. Typical shrub associates are low sagebrush (Artemesia arbuscula) or rigid
sagebrush (Artemesia rigida). The lower productivity results in sparse vegetation cover and consequently
Juniper Steppe PAG sites have much longer fire return intervals than Juniper Woodland PAG sites (80120 years versus 40-50 years).
Mesic (moist) Ponderosa Pine PAG – The Mesic Ponderosa Pine PAG is more productive and has a
different fire regime than the Dry Ponderosa PAG. Fuel conditions are variable, but are generally
intermediate between the Dry Ponderosa PAG and the Dry Grand Fir PAG. Ponderosa pine is the
principle tree species within the PAG, and pinegrass (Calamagrostis rubescens), elk sedge (Carex geyeri),
and snowberry are the most prominent understory species present (Simpson et al. 1994).
Moist Grand Fir PAG – In Moist Grand Fir PAG, typical understory species are queencup beadlily
(Clintonia uniflora), twinflower (Linnaea borealis), huckleberries (Vaccinium spp.) and Columbia brome
(Bromus vulgaris). The Moist Grand Fir PAG includes the most productive sites on the Forest, and occurs
at all but the highest elevations. The fire regime within this PAG consists of two types: (1) a high
frequency, low intensity regime which creates small openings in the canopy; and (2) a low frequency,
high intensity regimes which results in stand replacement burns over thousands of acres. Fire return
intervals are at least 40 to 50 years, and increase to 200+ years on the wettest sites. Live fuels in the form
of understory trees can add greatly to the crown fire hazard, especially under severe burning conditions
(Simpson et al. 1994).
Subalpine Fir PAG – This PAG occupies only a small percentage of the total acreage on the Forest. It
occurs at upper elevations with the coldest temperatures and most moisture on the Forest. In addition to
subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmanii), lodgepole pine (Pinus contorta),
and western larch (Larix occidentalis) occur. In addition, grand fir and Douglas-fir may occur in minor
amounts. Typical understory species are grouse huckleberry (Vaccinium scoparium), big huckleberry
(Vaccinium membranaceum), currants (Ribes spp.), heartleaf arnica (Arnica cordifolia) and elk sedge.
Shrubland PAG – Fifteen percent of the Ochoco NF is mapped as non-forested. These areas are basalt
tablelands or dry shrub-dominated areas that are dominated by one or more shrubs, including: low
sagebrush, mountain sagebrush (A. tridentata var. vaseyana), and rigid sagebrush along with bluebunch
wheatgrass, Sandberg bluegrass (Poa secunda), or Idaho fescue. Trees are absent or sparse. Surface fuels
comprise the majority of the fuel bed.
Page 7 of 11
Crooked River National Grassland – PAGs
Table 3 provides data on the Plant Association Groups (PAGs) found on the Crooked River National
Grassland (CRNG). A general description of each PAG follows Table 3; information is taken from
Simpson et al. (1994), and subsequent work by Michael Simpson.
Table 3. Total acres of mapped Plant Association Groups (PAGs) and relative percentages on the CRNG.
PAG
Dry Ponderosa Pine
Juniper Steppe
Juniper Woodland
Shrubland
CRNG
Acres
1,739
8,735
97,156
4,765
CRNG
% of Total
2
8
86
4
Dry Ponderosa Pine PAG – This PAG is found along the southwest fringe of the CRNG about 20 miles
southwest of Madras. Typical understory species are bluebunch wheatgrass (Pseudoroegneria spicata),
Idaho fescue (Festuca idahoensis), big sagebrush (Artemisia tridentata), antelope bitterbrush, curl-leaf
mountain mahogany (Cercocarpus ledifolius), western needlegrass (Achnatherum occidentale), and
arrowleaf balsamroot (Balsamorhiza sagittata). Downed, dead woody fuel loads are often light, but still
contribute 70 percent or more to the woody fuel load. Stands are characterized by discontinuous patches
of deep to very deep needle mat layers. The most abundant surface fuel is dead, or curing grass. Dwarf
mistletoe adds considerably to fuel loadings in infested stands (Simpson et al. 1994). Before 1900, fire
was a frequent event in ponderosa pine stands adjacent to western grasslands, occurring at intervals
between 5 and 25 years. The natural role of fire in this PAG is threefold: (1) to maintain grasslands
without western juniper or ponderosa pine; (2) to maintain open stands (parklands) and remove dense
understories of saplings, pole-sized trees, or (3) to thin overstory trees (Simpson et al. 1994).
Juniper Steppe and Juniper Woodland PAGs – Western juniper (Juniperus occidentalis) PAGs occur at
low elevations in the warmest and driest parts of the Forest (Simpson et al. 1994). Big sagebrush
(Artemesia tridentata), Antelope bitterbrush, Idaho fescue and bluebunch wheatgrass are typical
understory species. Downed, dead woody fuel loads are often light. Large downed fuels commonly
accounts for 70 percent or more of the total downed woody fuel load. Stands are characterized by
discontinuous patches of needle mat layers. The most abundant surface fuel is curing grass or shrubs such
as bitterbrush, or sagebrush on more productive sites (Simpson et al. 1994). Fire frequencies have
declined since 1900. Occurrence of fire has been reported to be reduced since this time by fire
suppression, reduction of understory fuels by domestic grazing, and construction of roads which act as
fire breaks (Burkhardt 1969).
Two PAGs occur on the CRNG. They differ primarily in the abundance of western juniper trees present
and in soils. The Juniper Steppe PAG occurs on shallow soils. These sites are much less productive than
the Juniper Woodland PAG sites. Typical shrub associates are low sage (Artemesia arbuscula) or rigid
sage (Artemesia rigida). The lower productivity results in sparse vegetation cover and consequently
Juniper Steppe PAG sites have much longer fire return intervals than Juniper Woodland PAG sites (80120 years versus 40-50 years).
Shrublands PAG –These areas are basalt tablelands or dry shrub-dominated areas that are dominated by
one or more shrubs, including: low sagebrush (Artemisia arbuscula), mountain sagebrush (A. tridentata
var. vaseyana), and rigid sagebrush (A. rigida) along with bluebunch wheatgrass, Sandberg bluegrass
(Poa secunda), or Idaho fescue. Fuel loads are comprised of surface fuels. Fire return intervals and fire
behavior vary with site characteristics, but are generally comparable to that of the Juniper Steppe and
Juniper Woodland PAGs, especially where juniper occurs at low density.
Page 8 of 11
Special Habitats – Deschutes NF, Ochoco NF
The following descriptions focus on the following special habitats: wetlands, riparian, meadows
(wet, moist, and dry), hardwoods (aspen stands and cottonwood bottomlands), and scablands.
Hardwoods – This type includes quaking aspen stands and black cottonwood (Populus
trichocarpa) bottomlands. These deciduous hardwood trees provide a variety of important
ecological functions, diversification of landscape patterns, and habitat for many other species
(USDA Forest Service 1997). Riparian communities composed of these species are typically
very rich in species and provide important structural diversity. Hydrologically, these habitats
provide important ecosystem services including: stream bank and soil stabilization, flood
resistance, and water temperature regulation. Soil fertility may be enhanced through
accumulation of leaf-litter.
Stream courses up to approximately 4,500 feet in elevation are often dominated by black
cottonwood (Populus trichocharpa), a short-lived species (USDA Forest Service 1997). Black
cottonwood stands often develop following flooding and deposition of sediment within
floodplains and valleys. Regeneration may be by seed, stump sprouting, and rooted cutting.
Quaking aspen (Populus tremuloides) grows in self-perpetuating clones in areas of locally high
moisture such as meadows, seeps, and stream sides.
Aspen and cottonwood are short-lived, early seral species that rely on disturbance for
establishment. Across a broader geographic area, black cottonwood has been declining due to
conversion of floodplain vegetation to agricultural uses, changes in stream systems (confining
streams into a single channel), over browsing by livestock, elk and deer, and conifer
encroachment (USDA Forest Service 1997). Quaking aspen is declining as a result of conifer
encroachment and increasing competition, from over-browsing by livestock, deer and elk, and
loss of habitat where the water table has dropped due to stream downcutting.
Meadows (dry, moist and wet) – Meadow communities occur in areas where groundwater is
higher than on adjacent upland sites, such as around a spring. Meadows often occur in the
vicinity of a water table next to streams. Moist meadows have moisture available in the rootingzone during the growing season, which drops 1-3 feet in the fall. Wet meadows are supported by
a water table at or near the surface throughout the growing season (Hall 1998). Dry meadows
have no standing water and dry out completely in the summer.
Riparian – Riparian areas include stream sides and adjacent upland areas. Plant communities
are influenced by stream shape, steepness, and flooding. Plant life is typically diverse, and is
characterized by a narrow band of moisture-loving plants directly adjacent to a stream, which
includes sedges (Carex species), rushes (Juncus species), and bulrushes (Scirpus species).
Riparian areas often receive moderate to heavy grazing use by wildlife and domestic livestock
(where it occurs). Roads and trails passing through or parallel to riparian areas can affect the
vegetation. Many roads are located along streams, contributing to direct loss or decline of
habitat. Streamside environments are desirable locations for camping and water recreation,
which can result in trampling of vegetation.
Page 9 of 11
Scablands – These are open, rocky areas with shallow soils having a high stone and rock
content. Trees are absent or sparse. Shrubs often include: low sagebrush (Artemisia arbuscula),
or rigid sagebrush (Artemisia rigida). Low-growing grasses such as Sandberg bluegrass (Poa
secunda) and herbs often predominate. Scablands are exposed to summer heat and drying of
soils, winter snow, and soil saturation in the spring. Livestock grazing is a predominant land use
within scabland habitats, although forage values are low.
Wetlands – Wetlands have at least one of the following features: 1) presence of water loving
plants (hydrophytes); 2) soils are wet throughout most or all of the summer (hydric soils); or 3)
the rooting substrate is non-soil and is either saturated or covered by shallow water at some time
during the growing season (Kovalchik 1987). Wetlands include:
Ponds – this habitat is a body of standing water and its associated edge of water-tolerant
vegetation. The pond may be permanent or seasonal.
Bogs and fens – A bog is a permanently wet area of rain and snow-deposited moisture
that is often dominated by sphagnum and other acid-tolerant plants. There is no outlet for
bog water, which often saturates the soil and slows decomposition of plant material. A
fen is fed by rainwater, snow melt, and underground springs which flow through a site,
providing oxygen to the soil and enhancing the decomposition of living and dead plant
materials. Both bogs and fens support a high number of plants, mosses, and lichens.
Swamps – A swamp is a permanently wet area, often shaded by a canopy of tall shrubs or
trees.
Acknowledgement:
Thanks to Emily Heyerdahl for review.
References
Burkhardt, J.W.; Tisdale, E.W. 1969. Nature and successional status of western juniper
vegetation in Idaho. J. Range Mgmt. 22:264-270.
Hall, F.C. 1998. Pacific Northwest Ecoclass Codes for Seral and Potential Natural
Communities. USDA Forest Service Pacific Northwest Research Station, General
Technical Report PNW-GTR-418.
Kovalchik, B.L. 1987. Riparian zone associations, Deschutes, Ochoco, Fremont, and Winema
National Forests. USDA Forest Service, Pacific Northwest Region, Region 6 Ecology
Technical Paper 279-87.
Simpson, M. 2007. Forested plant associations of the Oregon East Cascades. Tech. Pap. R6NR-ECOL-TP-03-2007. USDA Forest Service, Pacific Northwest Region.
Simpson, M.; Zalunardo, D.; Eglitis, A.; Wood, D.C.; Roy, D.; Johnson, S. 1994. Viable
Ecosystems Management Guide (draft). Ochoco National Forest, Prineville, Oregon.
108 p. + appendices.
USDA Forest Service. 1996. Metolius Watershed Analysis. Sisters Ranger District, Deschutes
National Forest, Sisters, Oregon.
USDA Forest Service. 1997. Mill Creek Watershed Analysis. Ochoco National Forest,
Prineville, Oregon.
Volland, L. A. 1985. Plant associations of the central Oregon pumice zone. U.S. Forest Service
Publication R6-ECOL-104-1985.
Page 10 of 11
Appendix 1. Common and scientific names
Common name
antelope bitterbrush
aquatic sedge
arrowleaf balsamroot
beaked sedge
bearberry
beargrass
big huckleberry
big sagebrush
black cottonwood
bluebunch wheatgrass
bottlebrush squirreltail
California blackberry
Cascade Oregongrape
chokecherry
Columbia brome
common prince’s pine
common snowberry
creeping snowberry
curl-leaf mountain mahogany
currants
Douglas’ spirea
Douglas-fir
dwarf rose
Engelmann spruce
few-flowered spikerush
Geyer's sedge
golden chinquapin
grand fir
greenleaf manzanita
grouse huckleberry
heartleaf arnica
huckleberries
Idaho fescue
incense cedar
kinnikinnick
Scientific name
Purshia tridentata
Carex aquatilis
Balsamorhiza sagittata
Carex utriculata
Arctostaphylos
nevadensis
Xerophyllum tenax
Vaccinium
membranaceum
Artemisia tridentata
Populus trichocarpa
Pseudoroegneria
spicata
Elymus elymoides
Rubus ursinus
Berberis nervosa
Prunus virginiana
Bromus vulgaris
Chimaphila umbellata
Symphoricarpos albus
Symphoricarpos mollis
Cercocarpus ledifolius
Ribes spp.
Common name
lodgepole Pine
long-stolon sedge
low sagebrush
mountain alder
mountain alder
Scientific name
Pinus contorta
Carex inops
Artemisia arbuscula
Alnus incana
Alnus incana
mountain hemlock
mountain sagebrush
Tsuga mertensiana
Artemisia tridentata var. vaseyana
mountain snowberry
Pacific silver fir
pinegrass
Symphoricarpos oreophilus
Abies amabilis
Calamagrostis rubescens
pinemat manzanita
pink mountain heath
ponderosa pine
quaking aspen
queencup beadlily
red osier dogwood
rigid sagebrush
Sandberg bluegrass
serviceberry
Shasta red fir
Spiraea douglasii
Pseudotsuga
menziesii
Rosa gymnocarpa
Picea engelmanii
Eleocharis pauciflora
Carex geyeri
Chrysolepis
chrysophylla
Abies grandis
Arctostaphylos patula
Vaccinium scoparium
Arnica cordifolia
Vaccinium spp.
Festuca idahoensis
Calocedrus decurrens
Arctostaphylos uvaursi
Sitka sedge
Smooth woodrush
Arctostaphylos nevadensis
Phyllodoce empetriformis
Pinus ponderosa
Populus tremuloides
Clintonia uniflora
Cornus sericeus
Artemisia rigida
Poa secunda
Amelanchier alnifolia
Abies magnifica
var. shastensis
Carex sitchensis
Luzula hitchcockii
snowbrush
sugar pine
tall Oregongrape
tufted hairgrass
twinflower
Ceanothus velutinous
Pinus lambertiana
Berberis repens
Deschampsia cespitosa
Linnaea borealis
wax currant
western bog blueberry
Western juniper
western larch
western needlegrass
white fir
widefruit sedge
willows
Ribes cereum
Vaccinium occidentale
Juniperus occidentalis
Larix occidentalis
Achnatherum occidentale
Abies concolor
Carex eurycarpa
Salix spp.
Page 11 of 11