Living on the Edge
Not all trees have economic or commercial value. They are however, important for wildlife and riparian values.
Because of Wyoming’s geographical location, it is the home of many range margin tree species. Its location at the intersection of the biomes of the Great Plains, Northern and Southern Rocky Mountains, and the Great Basin gives provides a mixture of species “living on the edge” with eastern, southern, northern and western species all living on their range margins in Wyoming.
The University of Wyoming, in conjunction with BLM Wyoming, put together a series of “Living on the Edge – Integrating Science into the Management of Range-Margin Populations” in 2010 and 2011 and can be found at: https://sites.google.com/site/rangemarginworkshop/
Some of the range margin tree species that BLM Wyoming manages are:
Whitebark pine (Pinus albicaulis), the iconic tree of the high windswept mountain tops. BLM Wyoming manages the far eastern and southern, east of the Great Basin ranges of this species.
- Limber pine (Pinus flexilis) is found along its eastern most range in Wyoming.
- Bur oak (Quercus macrocarpa) westernmost range is in northeastern Wyoming. The species provides valuable wildlife and watershed benefits. This white oak tree’s acorns are low in tannins and favored by many wildlife species, including wild turkeys.
- Paper birch (Betula papyrifera) is only found in the Black Hills of northeastern Wyoming. This species is normally found in Wisconsin, Minnesota and Canada. It grows in association with Black Hills spruce.
- Black Hills (white) spruce (Picea glauca var. densata) grows on BLM lands in the Black Hills. This species is normally found in Wisconsin, Minnesota and Canada. It grows in association with paper birch.
- Green ash (Fraxinus pennsylvanica) which at its farthest extent west, is found in the drainages of northeastern Wyoming.
- Box elder (Acer negundo) is found in the plains areas of northeastern Wyoming in drainages. Northeastern Wyoming is its farthest western extent.
- Pinyon pine (Pinus edilus) extends from the Southwest into the Great Basin. Its northernmost range is found in far southwestern Wyoming near Flaming Gorge Reservoir.
- Plains cottonwood (Populus deltoids spp. monilifera) is often associated with the Great Plains. Its presence indicated water and shade for wildlife and was used extensively by Native Americans and European pioneers. Its western-most range is in eastern Wyoming.
- Fremont cottonwood (Populus fremontii). This is the Western (Great Basin) equivalent of the Plains cottonwood. This species of cottonwood is found in some of the drainages of western Wyoming.
- Balsam poplar (Populus balsamifera) is a tree from the north. Its normal range is in Canada, the Great Lakes states and in the Northeastern states. It is found in a few isolated patches in Northeast Wyoming and in the Big Horn Mountains.
Tree range maps can be found at http://esp.cr.usgs.gov/data/atlas/little/.