Colorado Statewide Forest Resource Assessment

Oak ShrublandsOak shrublands cover approximately 2 million acres in Colorado betweenelevations of approximately 6,000 and 9,000 feet. These shrublands accountfor 10 percent of the forested lands in Colorado and are found throughoutmost of western Colorado, along the southern Front Range and in the centralpart of the state. Their appearance can range from dense thickets with littleunderstory to relatively moist sites with a rich understory of shrubs, grassesand wildfl owers. Fifty-seven percent of Colorado’s oak shrublands are inprivate ownership; the USFS and BLM are responsible for approximately 19percent and 18 percent, respectively.Fire usually plays an important role in maintaining oak shrublands; itpromotes regeneration, controls the invasion of trees, and increases thedensity and cover of Gambel oak and serviceberry (CNHP 2009). Many ofthese landscapes currently suffer from altered fi re regimes due to extensivefi re suppression, especially in the wildland-urban interface. Wildlife speciesassociated with oak shrublands include sharp-tailed grouse, mule deer, elk,Abert’s squirrels, black bears, blue grouse and Merriam’s turkey. Populationsof some shrubland birds have been in sharp decline for quite some time.Among these species is the green-tailed towhee – a typical inhabitant of oakshrublands. Oak shrublands is a primary habitat for 17 Species of GreatestConservation Need (CDOW 2006).Montane RiparianMontane riparian forests occur along rivers and streams in Colorado’s foothilland mountain regions, beginning around 6,000 to 7,500 feet in elevation.Montane riparian forests occupy roughly 1 million acres in Colorado andaccount for 4 percent of the state’s forested lands. These forests tend to bedominated by alder and blue spruce, but may be imbedded within severalother forest types, including ponderosa pine, aspen and spruce-fi r. The USFSmanages the majority of Colorado’s montane riparian (40 percent) and privatelandowners (36 percent). Riparian forests may be found within the fl oodzone of rivers, on islands, sand or cobble bars, and immediately adjacent tostreambanks. The health and sustainability of these systems depends on anatural hydrologic regime, especially annual to episodic fl ooding.In a semi-arid state such as Colorado, the benefi t of riparian areas to wildlifeoften is disproportionate relative to their size. The vast majority of speciesthat occupy montane habitats rely on riparian forests at some point in theirlife cycle. This is especially true of many amphibian species, as well as suchwater-dependent species as beaver and river otter. Elk, mule deer and moosealso favor montane riparian habitats. Boreal toads and northern leopard frogsare closely associated with montane riparian forests and adjacent wetlands– these habitats are especially important as breeding sites. Colorado’s mostimportant fi sheries are mountain streams surrounded by riparian forests. Morethan 50 percent of the state’s native fi sh are Species of Greatest ConservationNeed and nearly all rely on riparian forests to maintain healthy populations.Riparian forests, including both montane and plains types, also are importantfor a number of migratory and tree-roosting bats, including the red bat, silverhairedbat and hoary bat.Plains RiparianLow-elevation plains riparian systems are found along rivers and streamsthroughout the western Great Plains. At 250,000 acres, these forests representjust 1 percent of the state’s forested lands, but they support a tremendous12