Resistance, Resilience, and Transition Pathways
What is resistance?
Resistance actions are designed to work against the effects of climate change and maintain the forest in its current condition. In this way, resistance actions can be seen as “playing defense” in trying to prevent changes from occurring. When forests have low vulnerability to climate change, it may be relatively easy to maintain the current forest condition while climate change impacts are minimal. However, as climate impacts and vulnerabilities increase, the resistance pathway becomes increasingly challenging. Although resistance actions may be appropriate for defending high-risk or high-value resources in the short term, such as rare species or unique habitats, these actions may require considerable time and resources and ultimately become too costly to implement. Additionally, climate change may cause conditions in some areas to fundamentally change so that the resistance pathway is no longer feasible.
What is resilience?
Resilience actions focus on increasing the capacity of the ecosystem to cope with climate change and other stressors while maintaining its fundamental character. Resilience actions are designed to enable ecosystems to withstand a variety of stressors and to bounce back from disturbance. For example, greater diversity in ecosystems (in terms of species composition, species functional traits, or age distribution) is generally expected to increase resilience by allowing for multiple pathways for recovery after a disturbance. Resilience is a commonly discussed adaptation option and can be valuable in many systems, but it may not be appropriate in all situations. As with the resistance pathway, greater levels of impact and disturbance from climate change and other stressors will likely create greater challenges to maintaining the current ecosystems using resilience strategies alone.
What is transition?
Transition actions intentionally accommodate ecosystem change, rather than resist it. These actions work to move forests toward conditions that are expected to be better adapted to future conditions. These alterations vary across a continuum from slight changes in species composition and structure in response to expected change (e.g., anticipatory adaptation) to full-fledged transformation to novel communities. Transition approaches are likely unnecessary in ecosystems that are not highly vulnerable, and it may take extreme effort to “push” these systems toward altered conditions. Ecosystems that are highly vulnerable, especially those that have reduced adaptive capacity (e.g., degraded sites) or have undergone severe disturbance may be the most suitable locations to explore transition strategies. Because transition actions are often inherently experimental and outside of “business as usual” management, monitoring and evaluation activities take on even greater importance.
What is no action?
No Action - Landowners and forest managers can intentionally decide to take no action in managing their forests. Passive management, which allows forests to mature and be influenced by natural succession and disturbance dynamics rather than human intervention, can be an intentional management decision to help meet landowner goals. In the context of a changing climate, forests are subject to a wide array of changing weather patterns and climate conditions, regardless of whether they are actively or passively managed. Even if there is no active management, forests will continue to change over time as a result of natural processes, forest disturbances such as storms and pest outbreaks that may or may not be exacerbated by climate change, and the growing direct effects of climate change like warmer winter temperatures. The current condition of a site and its vulnerability to climate change and other stressors is likely to have a strong influence on how systems will change over time.