INTEGRATING CLIMATE CHANGE ADAPTATION APPROACHES INTO SILVICULTURAL PLANNING AND DECISION-MAKING

Natural resource managers are devising new tools and approaches to integrate climate change into silvicultural prescriptions. In addition to traditional metrics of treatment outcomes (i.e., species composition, productivity and forest health), scientists have begun including forest response to both imperceptible and extreme effects of climate. In the central Appalachian region of the eastern United States, geomorphological factors contribute spatially and temporally to the amount of physical damage, declines in forest health, and species-specific mortality. This presentation will address how silvicultural prescriptions are being refined to address forest resistance and resilience to 1)extreme weather events, and 2)invasions of exotic insects.

In late October 2012, the mixing of an arctic air mass with moisture from post-tropical cyclone Sandy resulted in over 2 feet of heavy, wet snowfall in the mountains and valleys of the central Appalachian Mountains. Forest damage was most extensive in West Virginia, where 1.5 million cubic yards of woody debris were scattered over 18 counties. Preliminary data from the Monongahela NF indicate that species that had not yet shed leaves were more vulnerable to stem and crown breakage, especially in the overstory canopy. Topographic features also influenced snow loading and damage severity.

The hemlock woolly adelgid (HWA) (Adelges tsugae) an exotic invasive insect, introduced from Asia in the 1980s, currently occurs in 17 eastern states. This aphid-like insect is unique in that the majority of its feeding occurs during the winter when potential predators are dormant and hemlock is still physiologically active. In the southern part of hemlock's range, HWA has caused rapid, widespread mortality of eastern and Carolina hemlocks (Tsuga canadendsis, T. Caroliniana). Further north, insect spread and tree mortality had been much slower because cold winter temperatures hamper HWA survival. Recent above-average winter temperatures have increased HWA spread rates northward and into higher elevations. Silvicultural thinning experiments are reducing stand densities and favoring the healthiest hemlocks prior to HWA infestation. Six years post-harvest, topographic features such as slope and aspect, appear to influence hemlock vulnerability to HWA more than treatment.