Approach
EASTERN: As populations experience cumulative changes in climate, or short-term extremes in climate, new selective pressures on populations may result in changes in phenotypic expression and genotypic evolution responses. Some genotypes may be better adapted to future conditions or changing conditions because of pest resistance, broad physiological tolerances, short regeneration times, or other characteristics. Identifying and managing these future-adapted genotypes during various life stages may allow a population to persist where it may otherwise fail. However, the use of this approach may be currently limited by the uncertainty about precise future conditions and which genotypes are best suited to these conditions. It is also possible that genotypes from other sites could interfere with the adaptation of local populations, if the imported resources are not adapted to withstand local pressures (e.g., frost tolerance or pathogen resistance). Availability of source material may also limit the use of this approach.
WESTERN: As populations experience cumulative changes in climate, or short-term extremes in climate, new selective pressures on populations may result in changes in phenotypic expression and genotypic evolution responses. Some genotypes may be better adapted to future conditions or changing conditions because of insect resistance, broad physiological tolerances, short regeneration times, or other characteristics. Identifying and managing these future-adapted genotypes during various life stages may allow a population to persist where it may otherwise fail. However, the use of this approach may be currently limited by the uncertainty about precise future conditions and which genotypes are best suited to these conditions. It is also possible that genotypes from other sites could interfere with the adaptation of local populations, if the imported resources are not adapted to withstand local pressures (e.g., frost tolerance or pathogen resistance). Availability of source material may also limit the use of this approach.
Tactics
- Planting stock from seeds collected from local trees that exhibit drought tolerance, pest resistance, or other desirable qualities.
- Planting stock from seeds collected from healthy trees in warmer or drier locations in the region.
- Retaining some survivors of a die-back event, such as drought-induced mortality or pathogenic blight, rather than salvage harvesting all trees in an affected area.
- Detecting and monitoring areas of natural regeneration in order to identify and promote well-adapted phenotypes.
- Planting disease-resistant chestnut in order to reestablish a form of this species on the landscape.
- Collecting, cultivating, and planting white pine blister rust-resistant sugar pine (Pinus lambertiana) and other white pines (e.g., whitebark pine) in order to maintain these important species on the landscape.
- Permitting forest managers and enabling private forest landowner to experiment with various lines of plant material types that might prove more climate adapted where experimental data are sparse.
Strategy
Strategy Text
Greater genetic diversity may help species adjust to new conditions or sites by increasing the likelihood that some individuals within a species will be able to withstand climate-induced stressors. Current guidelines for management of tree genes generally promote the conservation of local gene pools, restrict transfer of germplasm, and define small seed zones to minimize contamination between pools. A changing climate may require new guidelines that accommodate shifting seed zones and promote more options for increasing genetic diversity. Actions to enhance genetic diversity could be timed to occur after large-scale disturbances to take advantage of regeneration and establishment phases. Approaches under this strategy are best implemented with great caution, considering the uncertainties inherent in climate change, the sparse record of previous examples, the ecological and social suitability of particular locations, and continued uncertainties of forest response.
1. Swanston, C.W.; Janowiak, M.K.; Brandt, L.A.; Butler, P.R.; Handler, S.D.; Shannon, P.D.; Derby Lewis, A.; Hall, K.; Fahey, R.T.; Scott, L.; Kerber, A.; Miesbauer, J.W.; Darling, L.; 2016. Forest Adaptation Resources: climate change tools and approaches for land managers, 2nd ed. US Department of Agriculture, Forest Service, Northern Research Station. 161 p. http://dx.doi.org/10.2737/NRS-GTR-87-2,