Co-Conveners:

Jerry Franklin, University of Washington

Norman Christensen, Duke University

Rapporteur:

Allan Auclair, Resources for the Future

Fred Kaiser, USDA Forest Service

Archivists:

Dave Shriner, Oak Ridge National Laboratory

Steve McNulty, USDA Forest Service

Forest and forested landscapes are currently significantly stressed because of the scale and diversity of human demands and impacts on these ecosystems. There is an increased demand for all goods and services provided by forest ecosystems associated with increases in population and standard-of-living. Goods such as wood products are in high demand both nationally and globally. However, there is also greatly increased recognition of the importance of services provided by forest ecosystems, such as production of high-quality, well-regulated waterflows, wildlife, and recreational and aesthetic experiences. Balancing the multiple and often conflicting demands for various goods and services is difficult and complex.

Forests are also significantly stressed by disturbances and human activities, including past management and shifts in land use. Insect and disease epidemics are serious problems in both the eastern and western United States as a result of several causes including introduction of exotic pests, stresses from air pollution, and historical forestry activities. In the west the potential for catastrophic fire has increased in some regions as a result of past management including suppression of fire, harvest practices, and active creation of dense stands. Urbanization of forest landscapes is creating additional management problems, such as fragmentation.

Global change will provide significant additional stresses to forest ecosystems. Direct effects will include increased physiological stress on individual trees and stands. Reduced forest ecosystem capabilities can be expected, such as in overall productivity, provision of ecosystem services (such as regulation of the hydrologic cycle), and in maintenance of biological diversity.

The greatest short- and mid-term impacts of global change on forests are likely to result from altered disturbance regimes. Intact forests have significant abilities to tolerate changes in climatic conditions and may, therefore, undergo only gradual changes under climate change. Disturbances such as wildfire and windstorm destroy existing forests, however, and force trees to undergo a cycle of regeneration; seedling establishment is the stage of forest development at which the tree is most vulnerable to adverse climatic conditions. Global change is likely to increase the frequency, intensity, and scale of wildfire and windstorms in some regions resulting in direct losses of forest. Climatic warming or drying or both will also result in increased physiological stresses which, in turn, increases susceptibility to insects and diseases; increased mortality due to these causes may also increase the potential for wildfire.

Policy alternatives can exacerbate or reduce potential stresses from global change. Policies utilizing forests to sequester carbon can, for example, contribute to forest stability and, thereby, maintenance of key services such as regulation of hydrologic cycles and maintenance of forest biodiversity); programs for sequestration can also be designed to remove significant amounts of carbon from the atmosphere. As another example, implementing policies, such as substitution of biomass for fossil fuels, can have both positive and negative effects. On the one hand, use of biomass for fuel increases overall demand on forests for products. On the other hand, biomass plantations can be used as substitutes for harvesting of natural forests and in some regions biomass markets may provide opportunities to remove small diameter trees from overstocked and fire-prone stands.

Substantial information needs exist for understanding the response of forest ecosystems to global change. As with most sectors, it is critically important that models be developed which provide predictive information at the regional level and for "extreme" events which are related to disturbances, such as drought periods, intense fire weather, and windstorms. Analyses are needed of how different forest types and species vary with regards to susceptibility or risks associated with global change effects (both direct and indirect, as through disturbance regimes). Spatially explicit information collected by remote sensing and analyzed using Geographic Information Systems is critical to these analyses.

Development and analysis of new management approaches and alternative policies is critical. For example, detailed analyses are needed of the potential magnitude and ecological and economic effects of carbon sequestration markets, globally and regionally. Similar analyses are needed to compare the relative merits of traditional intensive plantation forestry and integrated approaches based upon ecosystem management; i.e., to compare approaches which allocate land to dominant uses with those which attempt to integrate uses within stands and landscapes.

Continued comprehensive information on the state of forest ecosystems is the most important single information need. Hence, development and implementation of a scientifically-credible, long-term monitoring program is critical at regional and national levels. Monitoring programs should be integrated with a continuing inventory program to provide current assessments of changes in forest land use and conditions.

Forests provide both unique opportunities and challenges in the context of global change. First, because forest ecosystems provide such a diverse and important array of goods and services for society, overall demands are large and potential conflicts among uses are numerous and often intense. Hence, social issues, including equity among user groups and generations, are very important when considering problems and policies associated with global change. Second, decisions regarding forests are of special concern because they have very long-term consequences. Policies once made and implemented are not easily reversed! Third, forests provide the unique opportunity for sequestering large amounts of carbon. Issues associated with utilization of this capability and with marketing of carbon sequestration are complex both ecologically and economically and, hence need substantial study. Nevertheless, this is an important and unique potential of forests.

Holistic analyses are needed of the economic, social, and ecological consequences of various forest policies under global change. These need to include the complexities of the relationships among various goods and services and between different regions at both the national and global level. However, humility will be critical in interpretation of these analyses and implementation of policies, regardless of how good they may appear at the outset.