Wednesday, August 5, 2009 - 2:10 PM

OOS 30-3: An ecosystem management strategy for Sierran Mixed-Conifer Forests

Peter A. Stine1, Malcolm North, Kevin O'Hara2, William Zielinski1, and Scott Stephens2. (1) USDA Forest Service, (2) University of California, Berkeley

Background/Question/Methods

Current Sierra Nevada forest management on National Forest lands is mired in controversy revolving around perceived conflicts over appropriate management objectives and uncertain outcomes.  Management objectives of the last ten or more years have been focused on near term objectives of strategically reducing fuels within the dense stands of forests subject to fire suppression of the last 100 years.  There is some uncertainty around the resulting response to planned treatments and significant concern around the effects to other natural resources such as sensitive wildlife species and water.  Moreover, the looming effects of climate change only add to the uncertainty and concern over forest response under varying alternative future management scenarios.  Without an explicit longer term strategy for a more comprehensive ecological restoration strategy across the landscape matrix, management response is likely to continue to be met with concern and public challenges.

Results/Conclusions

Summarizing recent scientific literature, we suggest managers produce different stand structures and densities across the landscape using topographic variables (i.e., slope shape, aspect, and slope position) as a template to capture the inherent variability of these complex landscapes.  This template of varying stand conditions leads to a variety of silvicultural treatments suited to the local conditions of solar insolation, soil moisture retention, and other local physical environmental characteristics that drive vegetation composition and structure. Local cool or moist areas, where historically fire would have burned less frequently or at lower severity, would have higher density and canopy cover, providing core habitat conditions for species tied to “old forest” conditions.  In contrast upper, southern aspect slopes would have low densities of large trees.  For thinning, marking rules would be based on crown strata or age cohorts and species, rather than uniform diameter limits applied to all species. Collectively our management suggestions emphasize the ecological role of fire, changing climate conditions, provisions for retention or restoration of sensitive wildlife habitat, and the importance of forest structure heterogeneity at  several nested spatial scales.