The Montane Ecosystem occurs at elevations between approximately 5,600 and 9,500 feet. Dry, south-facing slopes of the Montane often have open stands of large ponderosa pines. Spacing of ponderosa pines is somewhat related to available soil moisture. Grasses, other herbs and shrubs may grow between the widely spaced trees on dry slopes. As the pines become old, their bark changes from gray-brown to cinnamon-red, and the bark releases a pleasant fragrance when warmed by the sun. The long needles of ponderosa pines are attached to the stems in groups of two's and three's.
North-facing slopes of the Montane escape some of the sun's drying action, so their soils contain more available water. As a result, the trees grow closer together and competition for sunlight produces a tall, slender growth form. The trees may be a mixture of Douglas fir, lodgepole pine, ponderosa pine and an occasional Engelmann spruce. A few shade-tolerant plants grow on the floor of the forest.
Montane soils with high moisture content may support groves of quaking aspen, whose leaves turn golden-yellow in the autumn and whose whitish bark is easy to recognize. Along streams or the shores of lakes, other water-loving small trees may be found. These include various willows, mountain alder, and water birch with dark-colored bark. In a few places, blue spruce may grow near streams and sometimes hybridize with Engelmann spruce. Flat Montane valleys may frequently have water-logged soil and be unable to support growth of evergreen forests.
Plants and Animals of the Montane Ecosystem
Did You Know?
If the current amount of total nitrogen deposition measured at the high-elevation monitoring site in Rocky Mountain National Park (3 kg/ha/yr) was the same throughout the park, the amount of airborne nitrogen entering the park would be equivalent to 35,500 twenty-pound bags of fertilizer. More...