OOS 88

Extreme Disturbance Events Leading to Forest Ecosystem Change

Extreme disturbance events (EDEs), perturbations to ecosystems that are rare with respect to historical patterns, are increasingly recognized as potent drivers of forest change, impacting tree species physiology, populations, and communities. For example, punctuated droughts have been associated with hydraulic failure in tree species, contributing to regional forest declines across the globe. Despite the importance in EDEs, most global change research focuses on responses to changes in mean conditions rather than individual events. As a result, attribution of tree mortality or recruitment dynamics to specific causes and predictions of future forest change are suspect, providing forest managers and policy-makers with uncertain and/or biased information upon which they must base decisions. To explore the diversity of EDEs and their effects on forest ecosystems, this organized oral session will highlight forest ecosystem responses to EDEs by examining recent and future change to ecological perturbations. This session will incorporate research from a diverse suite of forest ecosystems investigated with approaches from various ecological disciplines. The objectives of this session are (1) to characterize the impacts of EDEs on forest ecosystems across a variety of scales, from individual trees to ecosystems to regions, and (2) to present strategies for incorporating EDEs into global change predictions, and thus natural resource decision-making. To underscore the generality of the issue, this session includes a group of speakers presenting research from different ecosystems, examining different EDEs, and using different analytical methods while addressing the implications for predicting future forest change. Speakers will present results for forest responses to EDEs across North American forests and will explore a variety of EDEs, including the drought, insect outbreak, hurricanes, and wildfire. Forest, species, and tree responses to EDEs are examined using methodologies common to many ecological disciplines, including ecophysiology, ecosystem ecology, paleoecology, and population ecology. This session will help focus on the need for better representation of EDEs in ecological research.