More grist for our continuing discussion of future forests and climate change. An open-access paper in Environmental Research Letters, “Biomass stocks in California’s fire-prone forests: mismatch in ecology and policy.” In essence, the authors suggest a shift in policy, based on likely forest-carbon scenarios, is in order.
A PR about the paper notes that “….between 2018 and 2019, forests in the region lost 1.1 million metric tons of stored carbon to drought, wildfire, and invasive pests. That loss represents a 35% decrease in stored carbon and calls into question the feasibility of California’s long-term carbon policy.”
This illustration accompanies a UC Berkeley article about the paper:
Much of this region is federal land, so the question for us here on Smokey Wire is how the USFS is to move forward with forest planning and management, given this scenario.
Restoration of fire-prone forests can promote resiliency to disturbances, yet such activities may reduce biomass stocks to levels that conflict with climate mitigation goals. Using a set of large-scale historical inventories across the Sierra Nevada/southern Cascade region, we identified underlying climatic and biophysical drivers of historical forest characteristics and projected how restoration of these characteristics manifest under future climate. Historical forest conditions varied with climate and site moisture availability but were generally characterized by low tree density (∼53 trees ha−1), low live basal area (∼22 m2 ha−1), low biomass (∼34 Mg ha−1), and high pine dominance. Our predictions reflected broad convergence in forest structure, frequent fire is the most likely explanation for this convergence. Under projected climate (2040–2069), hotter sites become more prevalent, nearly ubiquitously favoring low tree densities, low biomass, and high pine dominance. Based on these projections, this region may be unable to support aboveground biomass >40 Mg ha−1 by 2069, a value approximately 25% of current average biomass stocks. Ultimately, restoring resilient forests will require adjusting carbon policy to match limited future aboveground carbon stocks in this region.