Resistance and Resilience: A Conceptual Framework for Silviculture

TLDR

Forest management increasingly seeks to build resistance and resilience to disturbances under climate change, yet existing definitions are descriptive and lack prescriptive guidance. The authors present a conceptual framework that explicitly distinguishes resistance from resilience, assigns appropriate scales, and sets the context for evaluating silvicultural interventions. Resistance is defined as the influence of stand or landscape structure and composition on disturbance impact, while resilience is defined as the influence of disturbance on subsequent structure and composition, and the framework is applied to wildfire and spruce beetle scenarios. The framework demonstrates that attempts to build resistance to spruce beetle outbreaks are ineffective, directing silviculturists toward realistic resilience goals, and it is broadly applicable to various disturbances and forest types.

Abstract

Increasingly, forest management goals include building or maintaining resistance and/or resilience to disturbances in the face of climate change. Although a multitude of descriptive definitions for resistance and resilience exist, to evaluate whether specific management activities (silviculture) are effective, prescriptive characterizations are necessary. We introduce a conceptual framework that explicitly differentiates resistance and resilience, denotes appropriate scales, and establishes the context for evaluation—structure and composition. Generally, resistance is characterized as the influence of structure and composition on disturbance, whereas resilience is characterized as the influence of disturbance on subsequent structure and composition. Silvicultural utility of the framework is demonstrated by describing disturbance-specific, time-bound structural and compositional objectives for building resistance and resilience to two fundamentally different disturbances: wildfires and spruce beetle outbreaks. The conceptual framework revealed the crucial insight that attempts to build stand or landscape resistance to spruce beetle outbreaks will ultimately be unsuccessful. This frees the silviculturist to focus on realistic goals associated with building resilience to likely inevitable outbreaks. Ultimately, because structure and composition, at appropriate scales, are presented as the standards for evaluation and manipulation, the framework is broadly applicable to many kinds of disturbance in various forest types.