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Mixed Conifer Forests. Mixed Conifer Forests. * ~8,000-10,000 ft elevation. * 25-30 inches of precipitation/annually. * very complex and heterogeneous in structure, composition, and disturbance history. Ponderosa pine Pinus ponderosa. Douglas-fir Pseudotsuga menziesii.
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Mixed Conifer Forests * ~8,000-10,000 ft elevation * 25-30 inches of precipitation/annually * very complex and heterogeneous in structure, composition, and disturbance history.
Mixed Conifer Forests -most variable and complex of any forest type -received relatively little research attention Two general types: 1) Warm-dry Mixed Conifer 2) Cool-wet Mixed Conifer
Warm-dry Mixed Conifer -shares some of the major species of ponderosa pine forests -resembles ponderosa pine forests in terms of stand structure and disturbance regimes
Cool-wet Mixed Conifer -shares some of the major species of spruce-fir forests -similar stand structure and disturbance regime as spruce-fir
Warm-dry Mixed Conifer -lower elevations, southerly aspects -ponderosa pine, Douglas-fir, aspen, white fir, Gambel oak, other shrubs -recurrent, non-lethal fires (20-50 yr intervals); rare lethal fires (>100 yr intervals) -episodic establishment of pine and Douglas-fir, perhaps mainly after fire; adult trees survive non-lethal fire
Cool-wet Mixed Conifer -higher elevations, northerly aspects -white fir, Douglas-fir, aspen, blue spruce, snowberry, other shrubs -lethal fires at long intervals (>100 yr); occasional small non-lethal fires; landscape patch mosaic -episodic establishment of Douglas-fir, perhaps mainly after fire; aspen may dominate stand after lethal fire
EURO-AMERICAN SETTLEMENT FIRE SUPPRESSION GRAZING LOGGING