Interacting disturbance in forest ecosystems: Does disturbance memory affect resistance and resilience of forest productivity?

Project Overview
Research Core Areas: 
Project Abstract: 
Global change is altering disturbance regimes in terrestrial ecosystems, leading to more frequent and intense interactions among disturbances, which can result in compounding effects on ecosystem structure and function. One aspect of disturbance interactions that is poorly understood is the role of structural and functional legacies (or “memory”) of initial disturbance on the resistance and resilience of the ecosystem to subsequent disturbance. In forested ecosystems structural and functional characteristics of the canopy are an important component of ecosystem memory that likely strongly mediates the effect of interacting disturbances on ecosystem functioning, but is also strongly affected by variation in initial disturbance severity. The research program detailed here evaluates how disturbance memory (in the form of altered canopy structure and functional traits) affects ecosystem resistance and resilience to subsequent disturbance. A new experimental defoliation method will be overlaid onto an existing long-term experimental disturbance study to create a novel disturbance interaction experiment. The seed project proposed here will develop the methodology to produce canopy defoliation, assess effects of defoliation on canopy structure, and collect preliminary data on short-term disturbance resistance. The experimental framework, novel methods, and preliminary data collected in this seed project will form the basis for a subsequent proposal to the National Science Foundation Division of Environmental Biology Ecosystem Science Cluster, which will develop and test a new conceptual framework on the role of ecosystem memory in ecosystem response to disturbance. The work made possible by the seed funding will transform our understanding of the effect of disturbances (and altered disturbance regimes related to global climate change) on ecosystem functions such as C sequestration, which can be used to parameterize terrestrial ecosystem models and enhance our ability to predict the future of the globally important terrestrial C sink.