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G215 Pseudotsuga menziesii Middle Rocky Mountain Montane Forest & Woodland Group
Type Concept Sentence: This Pseudotsuga menziesii-dominated forest and woodland group occurs throughout the middle Rocky Mountains of central and southern Idaho, south and east into the Greater Yellowstone region, including the Bighorn, Gros Ventre and Wind River ranges of Wyoming, and north into Montana on the east side of the Continental Divide to about the McDonald Pass area and also along the Rocky Mountain Front region and central "sky island" ranges of Montana.
Common (Translated Scientific) Name: Douglas-fir Middle Rocky Mountain Montane Forest & Woodland Group
Colloquial Name: Middle Rocky Mountain Montane Douglas-fir Forest & Woodland
Hierarchy Level: Group
Type Concept: This group occurs throughout the middle Rocky Mountains of central and southern Idaho (Beaverhead, Lemhi, and Lost River ranges), south and east into the Greater Yellowstone region, and the Bighorn, Gros Ventre and Wind River ranges of Wyoming. It extends north into Montana on the east side of the Continental Divide, north to about the McDonald Pass area, and also into the Rocky Mountain Front region and central "sky island" ranges of Montana. This is a Pseudotsuga menziesii-dominated group without the maritime floristic composition; these are forests and woodlands occurring in the Central Rockies where the southern monsoon influence is less and maritime climate regime is not important. This group includes extensive Pseudotsuga menziesii forests, occasionally with Pinus flexilis on calcareous substrates, and Pinus contorta at higher elevations. True firs, such as Abies concolor, Abies grandis, and Abies lasiocarpa, are generally absent in these occurrences, but Picea engelmannii can occur in some stands. Pinus ponderosa is not common in this group. Understory components include shrubs such as Juniperus communis, Mahonia repens, Physocarpus malvaceus, and Symphoricarpos oreophilus, and graminoids such as Calamagrostis rubescens, Carex rossii, and Leucopoa kingii. The fire regime is of mixed severity with moderate frequency. This group often occurs at the lower treeline immediately above valley grasslands, or sagebrush steppe and shrublands. Sometimes there may be a "bath-tub ring" of Pinus ponderosa at lower elevations or Pinus flexilis between the valley non-forested and the solid Pseudotsuga menziesii forest. In the Wyoming Basins, this group occurs as isolated stands of Pseudotsuga menziesii, with Artemisia tridentata, Carex rossii, Leucopoa kingii, and Pseudoroegneria spicata.
Diagnostic Characteristics: These are Pseudotsuga menziesii-dominated forests and woodlands without the maritime floristic composition. They tend to be drier than Pseudotsuga menziesii-dominated forests further north in the Rockies, where the maritime climate regime provides more moisture during the growing season.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Need to re-assess the concept of this group in relation to ~Central Rocky Mountain Mesic Grand Fir - Douglas-fir Forest Group (G211)$$, ~East Cascades Mesic Grand Fir - Douglas-fir Forest Group (G212)$$, and ~Central Rocky Mountain Douglas-fir - Pine Forest Group (G210)$$. Also, its transition in the south to ~Southern Rocky Mountain White Fir - Douglas-fir Dry Forest Group (G226)$$ needs to be clarified. It seems this group would most appropriately contain Rocky Mountain associations wherein Pseudotsuga menziesii is the only conifer, hence forests and woodlands that are not mixed conifer. Certainly this group is outside the range of distribution of either Abies concolor or Picea pungens, which are major components of Southern Rocky Mountain forest groups. It also does not overlap with major interior Pacific Northwest forest types which are affiliated with a more maritime climate regime, where trees such as Abies grandis, Larix occidentalis, Pinus monticola, Thuja plicata, or Tsuga heterophylla occur. However, it does have some overlap with ~Central Rocky Mountain Douglas-fir - Pine Forest Group (G210)$$, and there are Pseudotsuga menziesii-dominated forests extending south in the Rockies well into New Mexico, so the floristic "transition" from middle to southern Rocky Mountains is not yet clear.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Forests and woodlands of evergreen conifers, with understory components of broad-leaved deciduous shrubs, evergreen needle-leaved shrubs, and grasses or dryland sedges.
Floristics: This group includes extensive Pseudotsuga menziesii forests, occasionally with Pinus flexilis on calcareous substrates, Pinus contorta at higher elevations and Juniperus osteosperma or Juniperus scopulorum. True firs, such as Abies concolor, Abies grandis, and Abies lasiocarpa, are generally absent in these occurrences, but Picea engelmannii can occur in some stands. Pinus ponderosa is also not common in this group. Understory components include shrubs such as Acer glabrum, Amelanchier alnifolia, Cercocarpus ledifolius, Linnaea borealis, Juniperus communis, Mahonia repens, Physocarpus malvaceus, Purshia tridentata, Spiraea betulifolia, Symphoricarpos albus, and Symphoricarpos oreophilus. Common graminoids include Calamagrostis rubescens, Carex rossii, Leucopoa kingii, and Piptatheropsis micrantha (= Piptatherum micranthum). Forbs are variable, but typical taxa include Arnica cordifolia, Osmorhiza berteroi, Thalictrum occidentale, Viola adunca, and species of many other genera, including Arenaria, Erigeron, Lathyrus, Lupinus, Fragaria, Galium, Penstemon, Vicia, and others. This group often occurs at the lower treeline immediately above valley grasslands, or sagebrush steppe and shrublands. Sometimes there may be a "bath-tub ring" of Pinus ponderosa at lower elevations or Pinus flexilis between the valley non-forested and the solid Pseudotsuga menziesii forest. In the Wyoming Basins, this group occurs as isolated stands of Pseudotsuga menziesii, with Artemisia tridentata, Carex rossii, Leucopoa kingii, and Pseudoroegneria spicata.
Dynamics: Successional relationships in this group are complex. Pseudotsuga menziesii is less shade-tolerant than many northern or montane trees such as Tsuga heterophylla, Abies concolor, Picea engelmannii, or Thuja plicata, and seedlings compete poorly in deep shade. At drier locales, seedlings may be favored by moderate shading, such as by a canopy of Pinus ponderosa, which helps to minimize drought stress. In some locations, much of these forests have been logged or burned during European settlement, and present-day stands are second-growth forests dating from fire, logging, or other stand-replacing disturbances (Mauk and Henderson 1984). Pseudotsuga menziesii forests were probably subject to a moderate-severity fire regime in presettlement times, with fire-return intervals of 30-100 years. Many of the important tree species in these forests are fire-adapted (Populus tremuloides, Pinus ponderosa, Pinus contorta) (Pfister et al. 1977), and fire-induced reproduction of Pinus ponderosa can result in its continued codominance in Pseudotsuga menziesii forests (Steele et al. 1981). Seeds of the shrub Ceanothus velutinus can remain dormant in forest stands for 200 years (Steele et al. 1981) and germinate abundantly after fire, competitively suppressing conifer seedlings. Some stands may have higher tree-stem density than historically, due largely to fire suppression.
Environmental Description: These are forests and woodlands occurring in the Central Rockies where the southern monsoon influence is less and maritime climate regime is not important. In the middle Rocky Mountains, Pseudotsuga menziesii forests occur under a comparatively drier and more continental climate regime, and at higher elevations than in the Pacific Northwest. Elevations range from less than 1000 m in the central Rocky Mountains to over 2400 m in the Wyoming Rockies. Lower elevation stands typically occupy protected northern exposures or mesic ravines and canyons, often on steep slopes. At higher elevations, these forests occur primarily on southerly aspects or ridgetops and plateaus. Annual precipitation ranges from 50-100 cm with moderate snowfall and a greater proportion falling during the growing season. Monsoonal summer rains can contribute a significant proportion of the annual precipitation in the southern portion of the range. Soils are highly variable and derived from diverse parent materials. Pseudotsuga menziesii forests are reported by most studies (Pfister et al. 1977, Steele et al. 1981, Mauk and Henderson 1984, Lillybridge et al. 1995) to show no particular affinities to geologic substrates. Rock types can include extrusive volcanics in the Yellowstone region, and sedimentary rocks elsewhere in the Rockies. The soils are typically slightly acidic (pH 5.0-6.0), well-drained, and well-aerated. They can be derived from moderately deep colluvium or shallow-jointed bedrock, and are usually gravelly or rocky.
Geographic Range: This group occurs throughout the middle Rocky Mountains of central and southern Idaho (Lemhi, Beaverhead and Lost River ranges), south and east into the Greater Yellowstone region, and south and east into the Wind River, Gros Ventre and Bighorn ranges of Wyoming. It extends north into Montana on the east side of the Continental Divide to the Rocky Mountain Front and east into the "sky island" ranges of central Montana. It may also occur in scattered patches in southeastern Oregon. Some associations placed in this group also occur in Colorado.
Nations: CA,US
States/Provinces: CO, ID, MT, OR?, UT, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.836655
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.2 Cool Temperate Forest & Woodland Formation | F008 | 1.B.2 |
| Division | 1.B.2.Nb Rocky Mountain Forest & Woodland Division | D194 | 1.B.2.Nb |
| Macrogroup | 1.B.2.Nb.2 Ponderosa Pine - Douglas-fir - Limber Pine Central Rocky Mountain Dry Forest Macrogroup | M501 | 1.B.2.Nb.2 |
| Group | 1.B.2.Nb.2.c Douglas-fir Middle Rocky Mountain Montane Forest & Woodland Group | G215 | 1.B.2.Nb.2.c |
| Alliance | A3462 Douglas-fir Middle Rocky Mountain Dry-Mesic Forest & Woodland Alliance | A3462 | 1.B.2.Nb.2.c |
| Alliance | A3463 Douglas-fir Middle Rocky Mountain Mesic-Wet Forest Alliance | A3463 | 1.B.2.Nb.2.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: < Interior Douglas-fir: 210 (Eyre 1980)
- Cooper, S. V., K. E. Neiman, R. Steele, and D. W. Roberts. 1987. Forest habitat types of northern Idaho: A second approximation. General Technical Report INT-236.USDA Forest Service, Intermountain Research Station, Ogden, UT. 135 pp. [reprinted in 1991]
- Daubenmire, R. F., and J. B. Daubenmire. 1968. Forest vegetation of eastern Washington and northern Idaho. Washington State University Agricultural Experiment Station Technical Bulletin No. 60. 104 pp.
- Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Lillybridge, T. R., B. L. Kovalchik, C. K. Williams, and B. G. Smith. 1995. Field guide for forested plant associations of the Wenatchee National Forest. General Technical Report PNW-GTR-359. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 335 pp.
- Mauk, R. L., and J. A. Henderson. 1984. Coniferous forest habitat types of northern Utah. General Technical Report INT-170. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 89 pp.
- Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. General Technical Report INT-34. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 174 pp.
- Steele, R., R. D. Pfister, R. A. Ryker, and J. A. Kittams. 1981. Forest habitat types of central Idaho. General Technical Report INT-114. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 138 pp.
- Steele, R., and K. Geier-Hayes. 1995. Major Douglas-fir habitat types of central Idaho: A summary of succession and management. General Technical Report INT-GTR-331. USDA Forest Service, USDA Forest Service Intermountain Research Station, Ogden, UT.