自然保护与休闲部保护·守护·共享
自然保护与休闲部
Due to the expected impact of the winter storm, all Virginia State Park overnight facilities will be closed from Friday, Jan. 23 through Tuesday, Jan. 27. This decision is based on the forecast for unsafe conditions and potential power outages. For updates click here.
目录云杉和冷杉林
该群落的特点是针叶林和混交林，上层主要以红云杉 ( Picea rubens ) 或弗雷泽冷杉 ( Abies fraseri ) 为主。类似的森林分布在从西弗吉尼亚州南部到北卡罗来纳州西部和田纳西州东部的阿巴拉契亚山脉。
Fraser fir forests reach their northern range limit in southwestern Virginia, where they are confined to elevations above 1,700 m (5,400 ft) on Mount Rogers in Grayson and Smyth Counties. Habitats are characterized by extremely acidic, organic-rich soils; cold microclimates; high rainfall; frequent fogs; and lush bryophyte cover. Understory layers are sparse, while mountain wood fern (Dryopteris campyloptera) and mountain wood-sorrel (Oxalis montana) dominate a relatively dense herb layer. Near the lower elevation limits, mixtures of Fraser fir and red spruce are characteristic. Fraser fir-dominated vegetation is seriously threatened by air pollution and destruction of fir stands by the balsam woolly adelgid (Adelges piceae), an introduced insect pest.
Red spruce (Picea rubens) forests similar in composition to those of the North Carolina and Tennessee high mountains are restricted to high-elevation slopes and summits of the Southern Blue Ridge (> 1,300 m [4,300 ft]) in Grayson, Smyth, and Washington Counties and Clinch Mountain (> 1,400 m [4,600 ft]) in Russell and Tazewell Counties. Environmental conditions are similar to those of the Fraser fir forests. Southern mountain-cranberry (Vaccinium erythrocarpum) and hobblebush (Viburnum lantanoides) are prevalent shrubs in the typical stands of these communities. A rarer community type features overwhelming shrub dominance by evergreen rhododendrons (Rhododendron maximum and Rhododendron catawbiense). Yellow blue-bead lily (Clintonia borealis), mountain wood fern (Dryopteris campyloptera), mountain wood-sorrel (Oxalis montana), shining clubmoss (Huperzia lucidula), and Canada mayflower (Maianthemum canadense) are abundant herbs rooting in the thick moss cover. As lower elevation limits are approached, co-dominance by hardwoods, particularly yellow birch (Betula alleghaniensis), increases.
Red spruce forests and spruce-hardwood mixtures also occur locally at high elevations of Allegheny Mountain (above 1,100 m [3,600 ft]) and Jack Mountain (above 1,280 m [4,200 ft]) in Highland County, but differ considerably from the Southern Blue Ridge and Clinch Mountain stands. At least two compositional variants, associated with submesic ridge crests and mesic stream-head valleys, are present on Allegheny Mountain. Distinctly southern species are nearly lacking from these forests, while northern species such as late lowbush blueberry (Vaccinium angustifolium), stiff ground-pine (Spinulum annotinum), prickly tree-clubmoss (Dendrolycopodium dendroideum), and staghorn clubmoss (Lycopodium clavatum), are abundant.
由于地理和海拔范围受限，该生态群中的所有群落类型都被认为是全球罕见的。红云杉林是弗吉尼亚州唯一适合北方飞鼠（ Glaucomys sabrinus fuscus ）生存的栖息地，北方飞鼠是联邦政府和弗吉尼亚州列为濒危物种。与云杉和冷杉林有关的具有全球或州重要性的其他动物包括侏儒蝾螈（ Desmognathus wrighti ）、韦氏蝾螈（ Plethodon welleri ）和该州濒危的雪鞋兔（ Lepus americanus virginianus ）。许多北方鸟类都依赖弗吉尼亚州高海拔针叶林进行繁殖，其中包括北美锯磨猫头鹰 ( Aegolius acadicus )、隐士画眉 ( Catharus guttatus )、红喉鸣禽 ( Setophaga magnolia )、金冠戴菊 ( Regulus satrapa )、红胸鳾 ( Sitta canadensis ) 和冬鹪鹩 ( Troglodytes troglodytes )。
参考文献：Adams（ 1991 ）、Bailey 和 Ware（ 1990 ）、Fleming 和 Coulling（ 2001 ）、Fleming 和 Moorhead（ 1996 ）、McLaughlin 等人（ 1987 ）、Pielke（ 1981 ）、Rawinski 等人（ 1994 ）、Rheinhardt 和 Ware（ 1984 ）、Smith 和 Nicholas（ 1999 ）、Stephenson 和 Adams（ 1984 ）、Stevens（ 1969 ）。
© DCR-DNH，加里·P·弗莱明。
下载下面列出的每个社区类型的组成汇总统计电子表格。
