Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. i United States JUjj Department of Forest Vegetation of the Agriculture Gunnison and Parts of the Forest Service Uncompahgre National Forests: Rocky Mountain Forest and Range A Preliminary Habitat Experiment Station Type Classification Fort Collins, r- -.v.---. Colorado 80526 05 Vera Komarkova, Robert R. Alexander, and Barry^^Johrt^on General Teclinical Report RM-163 MS 908826 USDA Forest Service August 1988 General Technical Report RM-163 Forest Vegetation of the Gunnison and Parts of the Uncompahgre National Forests: A Preliminary Habitat Type Classification Vera Komarkova, Research Associate University of Colorado Robert R. Alexander, Chief Silviculturist Rocky Mountain Forest and Range Experiment Station^ Barry C. Johnston, Ecologist USDA Forest Service, Rocky Mountain Region Abstract A vegetation classification based on a combination of concepts and methods developed by Braun-Blanquet and Daubenmire was used to identify 37 tentative forest habitat types on the Gunnison National Forest. Woodland habitat types comprised two series with a total of 3 habitat types, and forest habitat types included nine series with a total of 34 habitat types. A key to identify the habitat types is provided and the management implications associated with each are discussed. Cover Photo.— Subalpine forests near Los Pinos Pass, Gunnison National Forest. Headquarters is in Fort Collins, in cooperation with Colorado State University. Contents Page INTRODUCTION 1 STUDY AREA 1 PHYSIOGRAPHY AND GEOLOGY 1 CLIMATE 3 ECOLOGICAL TERMS AND CONCEPTS 4 METHODS 5 WOODLAND HABITAT TYPES 6 JUNIPERUS OSTEOSPERMA SERIES 6 /uniperus osteospermalSymphoncarpos oreophilus 6 QUERCUS GAMBELII SERIES 7 Quercus gambelii/AmeJanchier alnifolia 8 Quercus gambelii/Prunus virginiana 9 FOREST HABITAT TYPES 9 PINUS PONDEEOSA SERIES 9 Pinus ponderosalFestuca arizonica 9 Pinus ponderosalFestuca idahoensis 10 PICEA PUNGENS SERIES 11 Picea pungenslFestuca arizonica 11 Picea pungens/Amelanchier alnifolia 12 PSEUDOTSUGA MENZIESII SERIES 13 Pseudotsuga menziesii/Paxistima myrsinites 13 Pseudotsuga menziesii/Purshia tridentata 14 Pseudotsuga menziesii/Symphoricarpos oreophilus 14 Pseudotsuga menziesii/Carex geyeri 15 Pseudotsuga menziesii/Festuca idahoensis 16 Pseudotsuga menziesii/Jamesia americana 16 P0PL7LUS ANGUSTIFOLIA SERIES 17 PopuJus angusti/oha/AJnus incana-Swida sericea 17 POPULUS TREMULOIDES SERIES 18 Populus tremuIoides/ArctostaphyJos adenotricha 19 PopuJus tremuIoides/Festuca arizonica 19 PopuJus tremuJoides/Festuca thurberi 20 PopuJus tremuJoides/Symphoricarpos oreophilus 21 PopuJus tremuJoides/AmeJanchier aJnifoJia-Prunus virginiana 22 PopuJus tremuJoides/Pteridium aquiJinum 23 PopuJus tremuJoides/ThaJictrum /endJeri 24 PINUS CONTORTA SERIES 25 Pinus contorta/Juniperus communis 25 Pinus contoTtalCarex geyeri 26 Pinus contorta/Vaccinium scoparium 28 PINUS FLEXILIS SERIES 29 Pinus /lexiJis/Ciliaria austromontana 29 PINUS ARISTATA SERIES 29 Pinus aristatalFestuca thurberi 29 Pinus aristata/Juniperus communis 30 Pinus aristatalFestuca anzonica 30 ABIES LASIOCARPA SERIES 31 Abies Jasiocarpa/Carex geyeri 32 Abies lasiocarpa/Vaccinium scoparium 33 Abies Jasiocarpa/Vaccinium myrtiJlus 34 Abies Jasiocarpa/Juniperus communis 35 Abies lasiocarpa/Arnica cordifolia 36 Abies lasiocarpa/Senecio trianguJaris 37 Abies Jasiocarpa/PoJemonium puJcherrimum 38 Abies Jasiocarpa/CaJamagrostis canadensis 38 Abies iasiocarpa/Moss 39 KEY TO FOREST HABITAT TYPES 40 DISCUSSION 42 VALIDITY OF HABITAT TYPE CLASSIFICATION 42 VERTICAL ZONATION OF FOREST TREE SPECIES 42 VEGETATION CLASSIFICATION AND RECOVERY AFTER DISTURBANCE 44 ECOSYSTEM PATTERNS 45 FURTHER STUDIES IN RELATION TO THE HABITAT TYPES ... 46 LITERATURE CITED 47 APPENDIX 52 Forest Vegetation of the Gunnison and Parts of the Uncompahgre National Forests: A Preliminary Habitat Type Classification Vera Komarkova, Robert R. Alexander, and Barry C. Johnston INTRODUCTION They are intended for two primary audiences—forest managers and land-use planners who want a working Although forest vegetation on the Gunnison National tool to use on the Gunnison National Forest, and ecolo- Forest and adjacent areas had been studied previously, gists who want a research tool to use in related studies. this study is the first attempt to comprehensively cate- However, many of the habitat types reported here are gorize and describe all forested habitat types based on represented by only one or two stands and must be quantitative data. The flora of several specific regions recognized as preliminary. Further intensive sampling wfithin the study area have been investigated. The most must be conducted before results should be regarded as extensive study was by Barrell (1969), who listed the conclusive and before the extent of and variations within species occurring in the Gunnison Basin. Considerable habitat types can be estimated. research on vegetation in the Crested Butte area has been done by the Rocky Mountain Biological Laboratory in Gothic, Colo. Included in this effort were vegetation STUDY AREA descriptions of several biotic communities (Langenheim 1962], plant succession (Barclay 1941, McCuUough 1948), The study area includes the Gunnison National Forest and general ecology of aspen communities (Morgan and a small part [76,500 acres (30,970 ha)] of the Uncom- 1969). Adjacent to the Gunnison National Forest, Hoff- pahgre National Forest. This area encompasses 1,767,700 man and Alexander (1980, 1983) described 11 forested gross acres (715,670 ha) (fig. 1). The Gunnison National habitat types each on the Routt and White River National Forest extends southward from the Elk Mountains and Forests. Six of these also occur on the Gunnison National White River National Forest to the San Juan Mountains Forest. Hess and Wasser^ also described the forested adjacent to the Uncompahgre, San Juan, and Rio Grande habitat types on the White River National Forest. Eight National Forests. It extends eastward to the Sawatch of the 18 habitat types they identified also occur on the Mountains and the San Isabel National Forest; westward Gunnison National Forest. it is bordered by the Grand Mesa and Uncompahgre Na- In 1982, a cooperative study, jointly funded by the tional Forests and non-Forest Service lands. Elevations Rocky Mountain Forest and Range Experiment Station within the study area range from 6,440 feet (1,963 m) to and the Rocky Mountain Region, was started by Castle Peak at 14,265 feet (4,490 m). Komarkova-^ to (1) identify and describe forested and nonforested habitat types on the Gunnison National Forest and part of the Uncompahgre National Forest, PHYSIOGRAPHY AND GEOLOGY based on plots well distributed over the study area; (2) relate habitat types to environmental parameters; and The study area is geologically diverse, varying from (3) relate Gunnison National Forest habitat types to volcanic shaped mountains and mesas in the south, similar classifications in other Rocky Mountain forests. predominately sedimentary rocks and granites in the The habitat type classification completed in 1986 is north, and Precambrian and other rocks exposed by ero- based, in part, on concepts and methods developed by sion in the central part of the area (Barrell 1969). Upper Daubenmire and Daubenmire (1968) and modified by Cenozoic igneous rocks of the San Juan Mountains are Pfister and Arno (1980) and others, and in part on the predominately volcanic, while those of the Elk Moun- floristic-sociological Braun-Blanquet concepts (Westhoff tains are largely epizonal plutonic; the age and sequence and van der Maarel 1978). of petrologic types are similar in the two areas (Lipman Although Komarkova^ classified both forested and et al. 1969). Glacial events may have occurred throughout nonforested lands on the Gunnison National Forest, the the Holocene and may be continuing at present, as indi- results reported here are restricted to forest vegetation. cated by rock glaciers and small cirque glaciers (Meier- ding and Birkeland 1980). ^Hess, Karl, and Clinton H. Wasser. 1982. Grassland, shrubland, The Elk Mountain Range to the north is relatively small and forestland habitat types on the White River-Arapaho National [40 by 20 miles (64 by 32 km)] and lies in a northwest Forests. (Final report, 53-82FT-1-19, on file. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.) to southeast direction. Only the southern portion is in- cluded in the study area. Topography is dominated by ^Komarkova, Vera. 1986. Habitat types on selected parts of the cirques, glacial moraines, aretes, extensive talus ac- Gunnison and Uncompahgre National Forests. (Final report, 28K2-234, on file. Rocky Mountain Forest and Range Experiment cumulations, and rock glaciers; the latter are prevalent Station, Fort Collins, Colo.) in areas of igneous and coarse clastic rock. Fossil and 1 Denver/ 1-70 US-50 1-25 106" 12 15 Ouray , 37" 40' 00 Figure 1.— Gunnison National Forest and selected parts of the Uncompahgre National Forest showing study plots. possibly active frost features, such as stone polygons, In the south, the Elk Mountains consist of the turf-banked terraces, and rock stripes, occur. Most Oligocene West Elk Breccia bluffs of the Gunnison River streams originate in cirque ice fields. Although the high and floodplain alluvium. Some of the lower mountains erosion potential of the predominately sedimentary for- are capped with Miocene basalt flows with underlying mations contributes