Canadian Forest Service Publications
Critical seed transfer distances for selected tree species in eastern North America. Pedlar, J.H., McKenney, D.W., Pengxin, L., Journal of Ecology 2021;00:1–13.
Issued by: Great Lakes Forestry Centre
Catalog ID: 40320
Availability: PDF (download)
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Plain Language Summary
Forest planting events offer opportunities to enhance forest adaptation and growth through the selection of appropriate growing materials (seeds and seedlings). Critical to such efforts is knowledge of critical seed transfer distances (CSTD) – i.e., the climatic distance that seed sources can be moved before significant growth losses occur. We assembled and analyzed a significant amount of provenance data to derive CSTDs for five tree species in eastern North America: black spruce (Picea mariana), white spruce (Picea glauca), jack pine (Pinus banksiana), white pine (Pinus strobus), and yellow birch (Betula alleghaniensis). Specifically, we employed transfer functions in the form of quadratic regression models, to quantify the relationship between tree height growth and the climatic distance that seed sources were moved. The resulting regression models were generally noisy (i.e., had low r-square values) and calculated CSTDs were large, indicating that seed sources could be moved significant climatic distances (hundreds of kilometers) before height growth was less than 90 percent relative to that of the local seed source. These broad relationships, which were relatively consistent across the 5 tree species we studied, would allow considerable flexibility in resulting seed transfer systems; however, given the significant uncertainty surrounding climate change – particularly in the location and timing of extreme weather events – prudent application of seed transfer limits is likely appropriate. The CSTD values reported in our paper will support ongoing efforts to incorporate climate change into seed transfer systems in Canada.