Treesearch

Forest Service General Technical Report "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (hereafter GTR 220) (North et al. 2009) emphasizes increasing forest heterogeneity throughout a range of spatial scales including within-stand microsites, individual stands, watersheds, and entire landscapes. For fuels reduction, various landscape strategies have been proposed and modeled, but there are few conceptual models for integrating forest restoration and wildlife habitat at larger scales. General Technical Report 220 proposes varying forest structure, composition, and fuels...

Designing and implementing vegetation treatments that can move a forest landscape toward a desired future condition is often challenging. Faced with diverse stakeholder interests and the unknown effects of changing climate conditions, managers need to engage and build collaborative projects. One such effort is the Dinkey project designed to help restore a healthy, diverse, fire-resilient forest structure while maintaining and enhancing habitat for fisher (Martes pennanti) and California spotted owls (Strix occidentalis occidentalis). The project retained tree species and size classes that...

Prior to historical logging and fire suppression, forests of the Sierra Nevada were extremely heterogeneous. Frequent low- to moderate-intensity fire was partly responsible for this heterogeneity, which in turn helped make forests resilient to high-severity stand-replacing events. Early observers of forests on the west slope of the Sierra Nevada noted the arrangement of large trees as grouped or clustered (Dunning 1923, Show and Kotok 1924) (fig. 12-1). Show and Kotok (1924) described the mixed-conifer forest as "uneven aged, or at best even-aged by small groups, and is patchy and broken;...

Applying science to the practice of forest management is a difficult process. Scientific results tend to be expressed in terms such as variances, confidence intervals, and probability distributions. Rarely does science provide unequivocal information, yet land managers must make definitive decisions on the ground. The General Technical Report "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests," published by the U.S. Forest Service (hereafter GTR 220) (North et al. 2009) presented some important concepts for land managers to consider; however, implementation of these...

There are some topics that continue to be raised by managers that were not sufficiently addressed in the first and second edition of U.S. Forest Service General Technical Report GTR 220 "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests." All of them concern issues about where and when GTR 220 concepts apply and how these concepts relate to current management practices. The first section discusses the appropriate ecological conditions where GTR 220 concepts might be applied. The second section attempts to clarify the types and potential wildlife uses of defect trees in an...

An unexpected outcome of U.S. Forest Service General Technical Report PSW-GTR 220, "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (North et al. 2009), was how it generated discussion about a desired future condition for Sierra Nevada forests. The paper did not convey leading-edge research results or provide an exhaustive literature review. Rather it was an effort to take findings generally accepted amongst scientists, and synthesize them into a conceptual model for how Sierra Nevada forests might be managed. When the GTR has been used in implementing projects, the...

The photos in this appendix may help identify some of the unique branching formations or bole characteristics in trees that can make a tree particularly valuable for wildlife, either for nesting, roosting, and use as hunting perches, or other uses. We have organized these following Bull et al.'s (1997)3 focus on five conditions: live trees with decay, hollows or brooms, snags, and logs. We’ve also included in these photos examples of understory areas with vertical diversity and hiding cover created by the retention of understory saplings, intermediate-sized trees, hardwoods, and brush.

In recent years, bark beetles have caused significant tree mortality in the Sierra Nevada, rivaling mortality caused by wildfire in some locations. This chapter addresses two important questions: How can managers prepare for and influence levels of bark beetle-caused tree mortality given current forest conditions and future climate uncertainties? and How would the variable forest conditions suggested by U.S. Forest Service General Technical Report PSW GTR- 220, "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (hereafter GTR 220) (North et al. 2009), influence these...

Increasing human emissions of greenhouse gases are modifying the Earth's climate. According to the Intergovernmental Panel on Climate Change (IPCC), "Warming of the climate system is unequivocal, as is now evident from observation of increases in average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level" (IPCC 2007). The atmospheric content of carbon dioxide (CO2) is at its highest level in more than 650,000 years and continues to rise. Mean annual surface air temperatures in California are predicted to increase by as much as 10 °F (5.6 °C)...

Fishers (Martes pennanti) and American martens (M. americana) are carnivorous mustelids associated with late-successional forests. The distributions of both species have decreased in the Sierra Nevada and southern Cascade region (Zielinski et al. 2005). Fishers occur primarily in lower elevation (3,500 to 7,000 ft) (1067 to 3134 m) Sierran mixed-conifer and ponderosa pine forests, while marten distribution overlaps that of fishers but extends to much higher elevation (4,500 to 10,000 ft) (1372 to 3048 m) red fir and lodgepole pine forests. Fishers and martens have disproportionately large...