Mixed Conifer Forests Mixed Conifer Forests 8 000

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

White fir Abies concolor

Aspen (Populus tremuloides)

Blue Spruce (Picea pungens)

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 sprucefir 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 Douglasfir, 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 GRAZING FIRE SUPPRESSION LOGGING