United States Department of Agriculture Forest Resources Forest Service Rocky Mountain Research Station of the Shoshone May 2008 National Forest Jim Menlove About the author __________________________ Jim Menlove is an Ecologist with the Interior West Forest Inventory and Analy- sis Program, Rocky Mountain Research Station in Ogden, Utah. He began his Forest Service career as an employee of the Shoshone National Forest. Contents ___________________________________ Page Description of the Shoshone National Forest ................................................1 Forest land highlights of the Shoshone National Forest ..............................2 Nonreserved timberland highlights of the Shoshone National Forest .....9 The inventory methods .....................................................................................12 Documentation ...................................................................................................13 For further information .....................................................................................13 Rocky Mountain Research Station Natural Resources Research Center 2150 Centre Avenue, Building A Fort Collins, CO 80526-2098 Forest Resources of the Shoshone National Forest Jim Menlove The Interior West Forest Inventory and Analysis (IWFIA) describes the characteristics of the forest land sampled on Program of the USDA Forest Service, Rocky Mountain Re- the Shoshone. Forest land is land that is at least 10 percent search Station, as part of our National Forest System coopera- stocked (or formerly stocked) with live tally tree species and tive inventories, conducted a forest resource inventory on is greater than 1 acre in size and 120 feet wide. Based on the Shoshone National Forest using a nationally standardized tree species present, forest land is subdivided into timber- mapped-plot design (for more details see section “Inventory land, where most trees are timber species commonly used methods” page 11). This report presents the highlights of this for wood products (such as Douglas-fir and lodgepole pine), 1999 inventory using commonly requested variables and and woodland, where most trees often have a multi-stem summaries. The data could be summarized in other ways for growth form and are not typically used for industrial wood different purposes (see “For further information” on the inside products (such as junipers). Although woodland species were back cover). The information presented in this report is based measured on Shoshone FIA plots, they occurred as minor solely on the IWFIA inventory sample (USDA 1999). Supple- components of timberland types, so all of the forest land mentary documentation and inventory terminology can be was classified as timberland. Fifty–seven percent of the total located in USDA (2002). Additional data collected by the area on the Shoshone National Forest is in reserved designa- Shoshone National Forest and used separately or in combina- tion in the Absaroka-Beartooth, North Absaroka, Washakie, tion with IWFIA data may produce varying results. Changes Fitzpatrick, and Popo Agie Wilderness areas. The first part since the inventory, such as the impact of recent disturbances of this report focuses on forest resources of all the forest on the Forest have not been incorporated into this report. land administered by the Shoshone National Forest, includ- Annual inventories will soon replace periodic inventories to ing reserved lands. A subsequent section will address non- help monitor these changes at shorter intervals. reserved timberland and roadless areas. Description of the Shoshone National Forest Nonreserved forest land The Shoshone National Forest administers 2,436,850 Reserved forest land acres (USDA 2000; 2002) of which 61 percent is forest land, Nonforest and water and 39 percent is nonforest or water (fig. 1). This report 28% 39% 33% Figure 1— Percent area by land class and reserved status, Shoshone National Forest, 1999. 1 Forest land highlights of the the most common at 24 percent, followed in abundance by Douglas-fir at 22 percent. The lodgepole pine forest type Shoshone National Forest comprises 19 percent of the forest land area; whitebark pine, Forest type—Forest resources are often described using a 14 percent; spruce-fir, 12 percent; limber pine, 7 percent; forest type classification. Forest type refers to the predomi- and aspen, 2 percent. nant tree species in a stand, based on plurality of tree stock- Tree and stand size—The size distribution of trees is an ing. Stocking is an expression of the extent to which growing indicator of structural diversity. Figure 3 displays the distribu- space is effectively utilized by live trees. tion of the 600 million live trees on the Shoshone National Forest types are dynamic and can change slowly through Forest by diameter class. Overall, this shows a typical diam- forest succession, or rapidly due to disturbances such as log- eter distribution with a higher number of small trees than ging, fire, or insect and disease epidemics. Figure 2 presents large trees. Trees often reproduce prolifically, but thin out the distribution of forest land area on the Shoshone National naturally over time due to competition for resources. Forest by forest type. The Engelmann spruce forest type is Engelmann spruce Douglas-fir Lodgepole pine Figure 2—Percent of forest land Whitebark pine area by forest type, Shoshone National Forest, 1999. Forest type Spruce-fir Limber pine Aspen 0 5 10 15 20 225 Percent forest area 250 200 150 Million trees 100 Figure 3—Number of live trees by 2-inch diameter class on forest land on the Shoshone National 50 Forest, 1999. 0 25.0+ 1.0-2.9 3.0-4.9 5.0-6.9 7.0-8.9 9.0-10.9 11.0-12.9 13.0-14.9 15.0-16.9 17.0-18.9 19.0-20.9 21.0-22.9 23.0-24.9 Tree diameter classes (inches) 2 Stand-size class is a classification of forest land based trees compared to small-diameter trees are required to fully on the dominant diameter-size of live trees that contribute stock a site. Figure 4 shows a breakdown of forest land on the to stand stocking. Large trees are timber-type softwoods Shoshone National Forest by area and stand-size class. Sixty- and all woodland tree species 9.0 inches diameter and four percent of the stands have a majority of stocking from greater, and timber-type hardwoods 11.0 inches diameter large trees, while 8 percent are nonstocked. and greater; medium trees include timber-type softwoods Figure 5 shows the area of forest land by forest type and and all woodland tree species 5.0 to 8.9 inches diameter, stand-size class on the Shoshone National Forest. The two and timber-type hardwoods 5.0 to 10.9 inches diameter; most common forest types in the large tree class are the En- and saplings/seedlings comprise all trees under 5.0 inches gelmann spruce and Douglas-fir forest types, which together diameter. Nonstocked stands are typically those that have make up 54 percent of the large tree stands. Forty-six percent been recently disturbed by tree cutting, forest fire, or other of the stands in the medium tree class are the lodgepole pine large-scale change. For tree stocking, fewer large-diameter forest type. Large diameter Medium diameter Figure 4—Area of forest land by stand-size class, Stand-size class Shoshone National Forest, Saplings/seedlings 1999. Nonstocked 0 100 200 300 400 500 600 700 800 900 1,000 Thousand acres 300 Large trees Medium trees 250 Saplings/seedlings Nonstocked 200 150 Figure 5—Area of forest land by Thousand acres forest type and stand-size class, 100 Shoshone National Forest, 1999. 50 0 Engelmann Douglas-fir Lodgepole Whitebark Spruce-fir Limber pine Aspen spruce pine pine Forest type 3 Number of live trees—Another way to assess forest diver- total number of trees; subalpine fir, 21 percent; whitebark sity is by examining the composition of forest land by tree pine, 18 percent; lodgepole pine, 15 percent; Douglas-fir, diameter and species. Figure 6 shows the 600 million live 11 percent; limber pine, 6 percent; aspen, 5 percent; and the trees by species in three diameter-size classes. Fifty-seven remaining species in figure 6 comprise the final 1 percent. percent of all live trees on the Shoshone National Forest are Species that are scarce may not be encountered with the from 1.0 to 4.9 inches diameter, 25 percent are from 5.0 to extensive sampling strategy used for this inventory. 8.9 inches diameter, and 18 percent are 9.0 inches diameter Figure 7 shows the number of live trees by species and el- and greater. Engelmann spruce makes up 23 percent of the evation class. Elevation is closely correlated with variations in 100 90 1.0 - 4.9" 5.0 - 8.9" 80 9.0" and greater 70 60 Figure 6—Number of live trees 1.0 50 inch in diameter and greater on forest land by species and diameter-size Million trees 40 class, Shoshone National Forest, 30 1999. 20 10 0 Aspen Douglas-fir maple juniper Limber pine Blue spruce Utah juniper Subalpine fir Whitebark pine Lodgepole pine Rocky Mountain Rocky Mountain Engelmann spruce Species 10000-10780 9000-9999 8000-8999 Engelmann spruce Lodgepole pine 7000-7999 Whitebark pine Douglas-fir Elevation class (feet) Subalpine fir Limberi pine 6000-6999 Aspen Rocky Mountain juniper Blue spruce Utah juniper 5000-5999 0 20 40 60 80 100 120 Million trees Figure 7—Number of live trees 5.0 inches diameter and greater on forest land by species and elevation class, Shoshone National Forest, 1999. 4 local climate. Precipitation generally increases with rising ele- vation, while temperature decreases. Aspect complicates this general rule; allowing relatively warmer- and dryer-site spe- cies to grow at higher elevations on south- and west-facing slopes. These factors have a profound effect on competition between tree species. The Shoshone National Forest displays some distinct elevation patterns in tree distribution: white- bark pine and Engelmann spruce do well at higher elevations, while Douglas-fir is a dominant species at lower elevations.