Rural/Conservation Forestry (Reviewed May 2012) NR/FF/011 Utah Forest Types: An Introduction to Utah Forests Darren McAvoy, Mike Kuhns, Justin Black

or coniferous forests grow in upper elevation basins and This fact sheet describes Utah’s forest types – mountain slopes, and favor northern to eastern aspects. forests categorized by their mix of species and High elevation means more precipitation and cooler their ecological place in the landscape. temperatures, both good for trees. Lower elevation valley bottoms, on the other Introduction hand, have lower Utah is known more precipitation and for its red rock than water is available for its forests, but only near streams, trees cover about a so they tend to have third of the state. This no forests except equals over 15 million for cottonwoods acres of scattered and willows near forest and woodland those streams. Mid- found in locations elevation foothills where conditions are get slightly increased just right for trees. precipitation and tend About fi ve million of to have woodlands those acres are upland of drought-tolerant forests of aspen and trees like pinyons, various conifers. junipers, oaks, and The rest are lower maples. Often these elevation forests in Ponderosa pine in Bryce Canyon National Park woodlands are thickest foothills and along or are only present stream bottoms and are referred to as woodlands. on more northern and eastern aspects. South and west aspects are the hottest and driest and often won’t have Forests, Elevation, and Aspect any trees. Elevation and aspect play a signifi cant role in the ecology of Utah forests, mainly through their effect on water Other factors that determine where forests and woodlands availability. Generally, if enough water is available in the are found and how well they do include temperature, soil, soil, trees will be found. The most productive evergreen grazing/browsing, aggressive weeds, and fi re. Forest Types Aspen Type Quaking aspen (Populus tremuloides), or Forest and woodland ecological communities can be quakies, are Utah’s second most common forest type, better understood by separating them into categories covering over 1.4 million acres. They are best known for called forest types. Forest types are defi ned by their their brilliant yellow to orange fall color, and for being dominant tree species, each type having its own carved on by sheepherders and others. Aspen is found on ecological characteristics that respond to natural and relatively moist sites. The trees grow together in clones, human-caused disturbances in specifi c ways. Utah has or groups of stems that share the same root system and about 15 different forest types that include forest species genetic makeup. They can be found from canyon bottoms like quaking aspen, Engelmann spruce, Douglas-fi r, to upper elevation slopes and often grow with conifers lodgepole pine, and ponderosa pine, and woodland like subalpine fi r and spruce. Scientists have shown that species like pinyons, junipers, oaks, and maples. there are far fewer aspens in Utah now than in the 1800s, and are concerned that conifers are encroaching upon Pinyon-Juniper Type The forest type with the greatest traditional aspen habitat. The diversity and abundance of land area in Utah is pinyon-juniper (PJ), which generally forest fl oor plants in an aspen stand can be ten times that occurs in the foothills. Utah has two kinds of pinyons, found on the fl oor of a stand of evergreen trees. singleleaf (Pinus monophylla) and Colorado (P. edulis), and two tree-sized junipers (often called cedars), Utah (Juniperus osteosperma) and Rocky Mountain (J. scopulorum). They often grow together, but they also grow with other tree species like mountain-mahogany (Cercocarpus species), ponderosa pine, white fi r, or Douglas-fi r. PJ density has increased in the past century due to fi re suppression and grazing. These dense stands burn intensely, and some scientists fear that these intense fi res threaten the health and longevity of this forest type.

Aspen Type  1.4 million acres at 7,000 to 10,000 feet elevation.  Important for wildlife habitat, grazing, biodiversity, and aesthetics.  Easily regenerates after clearcutting or burning by producing numerous root sprouts; rarely reproduces from seed in the West.  Root damage during logging can reduce sprouting. Pinyon-Juniper Type  Initially out-competes associated conifers after a  8 million acres at 5,000 to 8,000 feet elevation. clearcut or fi re by sprouting from established root  Occupy the driest forested sites. system, forming large, genetically identical clones.  Nearly 60 percent of Utah forest cover.  Shade intolerant and short-lived, so lack of  Important for wildlife habitat and livestock grazing. disturbance eventually leads to replacement by  Used for fence posts and poles, fi rewood, mine more shade tolerant conifers like spruce and fi r; this props, charcoal, Christmas trees, and pinyon nuts. is common in Utah due to fi re suppression.  Widely distributed, from mixed stands in southern  Slowly spreads into non-aspen sites by root system Utah to pure juniper stands in northern Utah. outgrowth and sprouting.  The Raft River Mountains in northwest Utah are  Replacement of aspen by existing conifers can the northern-most range of singleleaf pinyon. be encouraged by cutting or girdling aspen while  High scenic/recreation value in some areas. leaving the conifers alone.  Pinyon engraver beetle signifi cantly affects both  Clearcutting a mixed aspen-conifer stand is likely species of pinyon. to lead to replacement with pure aspen. Douglas-fi r Type The next most common forest types Spruce-Fir Type Spruce-fi r is the fourth most common are those dominated by Douglas-fi r (Pseudotsuga coniferous forest type in Utah, and is generally found menziesii) and white fi r (Abies concolor). Douglas-fi r is at higher elevations. It occurs as stands of Engelmann very common and tends to grow in fairly pure stands, spruce (Picea engelmannii) mixed with subalpine fi r while white fi r is more scattered and less common. (Abies lasiocarpa) and in association with Douglas-fi r, These mid-elevation species cover more than one million white fi r, and aspen, as well as various pines. The great acres. Early pioneers sought out Douglas-fi r for building majority of spruce found in Utah is Engelmann spruce, material, sometimes calling it red pine because it is an while about fi ve percent is blue spruce (Picea pungens). evergreen with reddish heartwood. There are at least fi ve Spruce is an important timber species in Utah, valued for canyons in Utah named Red Pine. One easy identifi er for its clear, straight grain. Spruce is also used for house logs. Douglas-fi r is the mouse-tail bracts that stick out from A massive spruce beetle epidemic currently is devastating under the cone scales. much of Utah’s spruce forest.

Douglas-fi r Type  1 million acres at 6,000 to 9,000 feet elevation.  Important timber and recreation resource and Spruce-Fir Type provides critical wildlife habitat.  3/4 million acres at 8,000 to 10,000 feet elevation.  Refers to sites where Douglas-fi r could dominate,  Important for wood fi ber, though spruce is worth but other species may be present, including true considerably more than fi r; wildlife habitat, fi rs, spruces, and lodgepole and ponderosa pines. recreation, and watershed values also important.  Intermediate shade tolerance, so undisturbed  Highest elevation type; dominated by subalpine Douglas-fi r can be replaced by more shade tolerant fi r, which is very shade tolerant, and Engelmann subalpine fi r or Engelmann spruce; fairly common spruce, which is slightly less tolerant. in Utah due to fi re suppression.  Other associated species are lodgepole and limber  Use group selection or shelterwood for reproduc- pine, Douglas-fi r, and aspen. tion since most associated species need protection  Regeneration after harvest is diffi cult; group to regenerate naturally or as planted seedlings. selection and shelterwood methods can be used;  Clearcutting if aspen or lodgepole pine is present protection is needed for seedling survival; planting will likely regenerate the stand to those species. and protection of advanced regeneration help.  Careful overstory removal can encourage natural  Stands can be very complex in structure and age regeneration where adequate advanced regeneration distribution; group shelterwood can be used in more is present. uneven-aged stands; openings should be less than  Clearcutting or overstory removal without adequate two times tree height for good protection. advanced regeneration will convert to shade  Fires are infrequent but important in dry years; intolerant species or to a poorly stocked stand of windthrow is an important disturbance factor. shade tolerant species such as subalpine fi r.  Root disease, bark beetles, and western spruce  Important pests are western spruce budworm, budworm are signifi cant pests; to control spruce bark beetles, and dwarf mistletoe; to control and beetle, remove attacked or susceptible trees and improve stand vigor, increase species and age-class treat slash. diversity. Pine Types Several pine forest types exist in Utah, Limber Pine Limber pine (Pinus fl exilis) tends to occupy including ponderosa, lodegpole, limber, and bristlecone the higher ridges in Utah. Although limber pine occupies types. Pines are intolerant of shade and more drought less than a million acres in Utah, its common name, tolerant than many of their associated species. “white pine,” honors 19 place names in the state.

Ponderosa Pine Ponderosa pine (Pinus ponderosa) is the Bristlecone Pine Bristlecone pine (Pinus longaeva) pine of Bryce Canyon National Park, and is found from occupies a very small range in Utah, mostly on upper the Uintas south. Ponderosa is our largest pine, eventually elevation plateaus in southern and western Utah. This getting an orange-yellow bark that earns it the name species is best known for including the oldest living tree, yellow pine, as in Yellow Pine Campground on the Uinta and perhaps the oldest organism, on Earth. National Forest. Oak-Maple Type Gambel oak (Quercus gambellii) Lodgepole Pine Lodgepole pine (Pinus contorta) covers and canyon or bigtooth maple (Acer grandidentatum) nearly a half million acres in Utah, mostly at higher woodlands occupy our lower mountain slopes and elevations in and north of the Uintas. Lodgepole is foothills, and offer outstanding fall color. As urban relatively short-lived (150 years), but it grows straight development expands and more homes are built in these and tall on good sites. It is used for lodge poles and fence woodlands, their management is increasingly important to poles, as well as lumber. prevent fi re disasters.

Pine Types Oak-Maple Type  Total of 1.1 million acres of pines at 7,000 to  Common native species on lower elevation foothills 10,000 feet elevation, depending on species. in Utah, between 5,000 and 7,800 feet.  Ponderosa pine naturally grows in open, park-like  Important for birds and big game. stands maintained by frequent fi re; fi re suppression  Although they often grow together, oaks prefer leads to dense stands; thick bark protects older southern aspects while maples prefer northern and trunks from fi re damage; commercially valuable. eastern aspects.  Lodgepole pine tends to grow in pure stands that  Oak is fi re adapted; it grows back quickly from root regenerate quickly after a fi re from seed; some trees sprouts after a fi re kills the tree tops. have serotinous (closed) cones that open after a fi re  Oak tend to be scrubby small trees less than 30 feet to release their seeds; commercially valuable. in height, but can reach 60 feet tall.  Limber pine occupies cold, windy, steep, rocky  Maple tends to have several stems and can reach 50 sites, often near tree line; not commercial; feet in height. regeneration depends on seed caches made by birds like Clark’s nutcracker; some Utah limber pines are More Infomation over 2,500 years old. For more information on Utah’s forests and woodlands visit the Utah State University Forestry Extension Web site at http://extension.usu.edu/forestry.

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