An ecosystem management strategy for Sierran mixed-conifer forests

Abstract

The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of multiple use management of the Nation's forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives-as directed by Congress-to provide increasingly greater service to a growing Nation. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.

Impacts of fire exclusion and recent managed fire on forest structure in old growth Sierra Nevada mixed-conifer forests

“…3), suggesting that average conditions alone are very much an oversimplification of historical forest conditions (Stephens and Gill 2005). As such, the historical data we present do not support the idea of basing management targets for restoration and forest resilience treatments on mean values (North et al 2009b). Perhaps the ranges in canopy cover, tree densities by size classes, and live tree carbon can serve as quantitative justification for implementing variable targets for restoration and forest resilience treatments.…”

Climate change vulnerability assessment of forests in the Southwest USA

“…For example, ecologists studying the role of highintensity fire in forested ecosystems of CA agree that fire suppression has degraded ecosystem integrity (Minnich et al 1995;Stephens and Ruth 2005;Spies et al 2006), but disagree on the appropriate response to the potential risk of high-intensity wildfire to reduce that stand density (Lee and Irwin 2005;North et al 2009;Hanson and Odion 2014). Disagreement on management objectives and on methods for achieving them could constrain the adaptive management of given forest types.…”

“…Among adaptation options, striving for forest resilience is the most hopeful (Hansen et al 2003) as resilient forests may accommodate gradual changes and return toward a prior condition after disturbance, either naturally or with management. Restoring resilience has become a touchstone for forest management across much the study region (North et al 2009;Stine et al 2014), perhaps because it is a conservative adaptation strategy, fundamentally following the definition of restoration in terms of maintaining historical representation in composition, structure, pattern, and processes (US Forest Service 2014). Management tools to increase resilience include combinations of mechanical treatment, prescribed fire, managed wildfire, and untreated control sites.…”

Effects of fuel treatments on California mixed-conifer forests

“…Until the early 20th century, those frequent low-to moderate-intensity fires with smaller patches of high-severity effects reduced the quantity and continuity of fuels in YPMC forests and created a complex patchwork of mixed-age tree clumps and gaps (Agee and Skinner 2005;North et al 2009). Since then, however, fire exclusion practices, logging of large trees and livestock grazing have allowed fuel and young trees to accumulate in some stands for a century or more, leading to high loads of spatially continuous fuels (Barbour et al 1993;Stephens and Ruth 2005) and increased risk of tree mortality from moisture stress and tree pests (Fettig et al 2007;van Mantgem and Stephenson 2007).…”