| Popis: |
Four general post-fire successional pathways leading to a climax Engelmann spruce (Picea engelmannii Parry)/subalpine fir (Abies lasiocarpa [Hook] Nutt.) forest were identified operating on the T.W. Daniel Experimental Forest in northern Utah. These included initial colonization by seral quaking aspen (Populus tremuloides Michx.), seral lodgepole pine (Pinus contorta Dougl. ex Loud.), colonization by lodgepole pine followed by a low intensity surface fire, and immediate colonization by late successional Engelmann spruce and subalpine fir. Post-fire establishment of the late successional species occurred earliest in the Engelmann spruce/subalpine fir pathway followed by the lodgepole pine and lodgepole pine ground fire pathways, and the quaking aspen pathway . The late successional species 11 grew fastest in the Engelmann spruce/subalpine fir pathway followed by the quaking aspen, lodgepole pine, and lodgepole pine ground-fire pathways. Conceptual models were presented showing how perturbations by fire, insect epidemics, and disease could interact to influence succession and shape the subalpine landscape. The subalpine forest changes through time to facilitate different types of disturbance that have varying effects on succession. In the continued suppression of fire, species and age class diversity will be reduced and disturbances may occur that are larger and more intense than those that have occurred historically. |
