Suppression of fire and removal of biomass after a fire are thus causes of reduced biodiversity and ecological integrity. Many effects of fire cannot be mimicked by land-use disturbances ( Odion and Sarr 2007). Low to moderate fire severities create fine-grained, lower contrast heterogeneity that generate very little if any CESFs, although they create other conditions favorable to biodiversity. In general, mixed-severity fires, which include patches of high-severity fire, create coarse-grained, high-contrast heterogeneity that results in CESFs, and, over time, a complex mosaic of serai stages at the landscape and local scales. Where these legacies are intact, complex early successional forests (CESFs) develop with rich biodiversity due to the function of the remaining biomass in providing resources to many life forms and because of habitat heterogeneity provided by mixed-severity fires that generated them ( Odion and Sarr 2007 Swanson et al. Such forests are generated by disturbances that reset successional processes and follow a pathway that is influenced by biological legacies (e.g., large live and dead trees, downed logs, seed banks, resprout tissue, fungi, and other live and dead biomass) that were not removed during the initial disturbance ( Franklin et al. We recommend eight best management practices in CESFs for achieving ecological integrity on federal lands in the mixed-conifer region of the Sierra Nevada.Įarly serai forests are ecosystems that occupy potentially forested sites after a stand-replacement disturbance and before re-establishment of a closed forest canopy ( Swanson et al. Thus, we describe important ecological attributes of CESFs and distinguish them from early serai conditions created by logging. CESFs have received little attention in conservation and reserve management. Ecologically detrimental management of CESFs, or unburned forests that may become CESF's following fire, is degrading the region's globally outstanding qualities. Severe fires are, therefore, essential to the region's ecological integrity. These forests support diverse plant and wildlife communities rarely found elsewhere in the Sierra Nevada. In the Sierra Nevada of California, CESFs are most often produced by mixed-severity fires, which include landscape patches burned at high severity. Such young forests contain numbers and kinds of biological legacies missing from those produced by commercial forestry operations. Complex early seral forests (CESFs) occupy potentially forested sites after a stand-replacement disturbance and before re-establishment of a closed-forest canopy.
0 Comments
Leave a Reply. |