Name:
Picea engelmannii - Abies lasiocarpa - Pinus contorta Dry-Mesic Forest & Woodland Group
Reference:
NatureServe Biotics 2019
Description:
Engelmann spruce and subalpine fir forests comprise a substantial part of the subalpine forests of the Cascades and Rocky Mountains from southern British Columbia east into Alberta, and south into New Mexico and the Intermountain West region. They also occur on mountain "islands" of north-central Montana. They are the matrix forests of the subalpine zone, with elevations ranging from 1275 m in its northern distribution to 3355 m in the south (4100-11,000 feet). Despite their wide distribution, the tree canopy characteristics are remarkably similar, with <i>Picea engelmannii</i> and <i>Abies lasiocarpa</i> dominating either mixed or alone. <i>Pseudotsuga menziesii</i> may persist in occurrences of this group for long periods without regeneration. <i>Pinus contorta</i> is common in many occurrences, and patches of pure <i>Pinus contorta</i> are not uncommon, as well as mixed conifer/<i>Populus tremuloides</i> stands. In some areas, such as Wyoming, <i>Picea engelmannii</i>-dominated forests are on limestone or dolomite, while nearby codominated spruce-fir forests are on granitic or volcanic rocks. Upper elevation examples may have more woodland physiognomy, and <i>Pinus albicaulis</i> or <i>Pinus flexilis</i> can be a seral component. Relatively xeric understory species are diagnostic of this group and may include <i>Amelanchier alnifolia, Juniperus communis, Mahonia repens, Physocarpus malvaceus, Shepherdia canadensis, Vaccinium myrtillus</i>, or <i>Vaccinium scoparium</i>. In the Bighorn Mountains, <i>Artemisia tridentata</i> is a common shrub. These forests often represent the highest elevation forests in an area. Sites within this group are cold year-round, and precipitation is predominantly in the form of snow, which may persist until late summer. Snowpacks are deep and late-lying, and summers are cool. Frost is possible almost all summer and may be common in restricted topographic basins and benches. Disturbance includes occasional blowdown, insect outbreaks and stand-replacing fire. Mean return interval for stand-replacing fire is 222 years as estimated in southeastern British Columbia.
Accession Code:
urn:lsid:vegbank.org:commConcept:40014-{FD1D9309-ED2D-484B-9436-15C0B3AA78F9}
Plot-observations of this Community Concept:
0
|
