bloom in meadows from June through August. Common animals in this zone include the hermit thrush, dusky grouse (Dendragapus obscurus), great grey owl, golden-mantled ground squirrel, and (more rarely) the marten. Upper montane forests may be viewed from the Tioga Pass Road east of Crane Flat, Glacier Point Road, and State Route 108. The elevation of the upper montane zone shifts with latitude: it occurs from north of Yosemite, and to the south. Subalpine Forest The upper montane forest is replaced by the subalpine forest near , where the climate is cooler with an even shorter growing season due to long, cold, and snowy winters. Accumulations of three to nine feet (1 to 2.5 m) of snow are typical. The most common tree in the subalpine forest is the whitebark pine. The western white pine, mountain hemlock, and lodgepole pine are also found in this forest with many subalpine meadows that flower from July through August. Many species live in, or are transient in, this zone, including Clark's nutcracker. The vegetation and ecology is determined by the harsh climate, with extensive snow and wind. In addition, soils are thin and nutrient-poor. Due to these harsh conditions, vegetation grows slowly and at low temperatures. In addition, the stressful environment suppress species competition and promotes mutualism. The marginal conditions make the Sierra Nevada subalpine zone sensitive to environmental changes, such as climate change and pollution. South of Bridgeport, the subalpine forest ranges from of elevation and contains foxtail pines, while to the north, the subalpine forest ranges from and the foxtail pine is absent. Alpine Zone The alpine zone begins near elevation (in the southern Sierra) and near (in the north). This zone is easily distinguished as it is above the tree line. No trees grow in this zone due to the harsh climatic conditions. Short, cool summers with long, cold, and snowy winters are typical at these elevations. Many exposed granitic outcroppings, talus slopes, and boulder fields limit the amount of vegetation that grows here. The herbaceous plants need to flower and produce their seeds quickly during the short, frost-free period of summer. Flora includes cushion plants, grasses, willows, and sedges. The macrolichen flora in the Sierra Nevada alpine zone is not well developed as compared to neighboring alpine zones in the Rocky Mountains and mountains of the Pacific Northwest. Some animal species that are adapted to this zone include the