Approach
Species are vulnerable to stressors at different stages in their life cycle. Even-aged stands are often more vulnerable to insect pests and diseases, many of which are likely to increase in range and severity as a result of climate change. Uneven-aged systems may expose a smaller proportion of the population to a particular threat at any one time, which can increase the resistance or resilience of a stand to a wider range of disturbances. Maintaining a mix of ages, sizes, or canopy positions will help buffer the overall stand to stressors specific to a single age class. Likewise, stands with higher species diversity may be less vulnerable to climate change impacts and disturbances because they distribute risk among multiple species, reducing the likelihood that the entire system will decline or lose productivity even if one or more species suffer adverse effects. Even small increases in species diversity in low-diversity stands or communities may strongly increase resilience without distinctly altering species composition.
Tactics
- Emulate natural disturbances through forest harvest techniques such as variable-density treatments or irregular return intervals in order to encourage the development of multiple age cohorts
- Planting species with a diverse timing of phenological events (e.g. flowering, fruiting, leaf out, leaf drop) to provide necessary resources over a longer time frame to forest-dependent wildlife species.
- Use scarification, planting, nurse logs, tip-up mounds, or other techniques to support natural regeneration.
- Focusing salvage operations on creating desired residual stand structures following disturbance, even if less merchantable timber is removed as a result.
- Release existing wetland seed banks by restoring historic water levels, or by removing sediment 'overburden'.
- Planting desired native species within an area that is otherwise expected to regenerate naturally in order to add diversity.
Strategy
Strategy Text
This strategy addresses the benefits of healthy forest cover in the production of water resources. It is well established that forested watersheds provide multiple benefits and ecosystem services such as timber, carbon storage, wildlife habitat, food, and cultural services. Changes to forest structure and composition, can alter underlying hydrologic processes within a watershed affecting the capture, storage and filtration of water, and the regulation of streamflow. Managing forests to reduce stressors, increase structural and species diversity, and protect unique habitats, may enhance forest ecosystem resilience to increasing climate variability, extreme events, and other disturbances.
Shannon, P.D.; Swanston, C.W.; Janowiak, M.K.; Handler, S.D.; Schmitt, K.M.; Brandt, L.A.; Butler-Leopold, P.R.; Ontl, T.A. (in review). Adaptation Strategies and Approaches for Forested Watersheds. Ecological Applications.,