Provisional Seed Zones: Indispensable Tools for Forest Conservation Assessment

Tree species exhibit a great deal of spatial genetic variation across broad scales. Understanding the degree and extent of genetic variation within species is an important component in conservation assessments both within and across tree species. Our understanding of spatial genetic variation is limited or nonexistent for most North American tree species, however. Quantifying spatial genetic variation within a single species is time-consuming and expensive, and even when such information exists, comparing between species is a challenge. Provisional seed zones – those applicable across species and determined based only on environmental information rather than direct provenance growth tests – therefore can be useful when it is important to define seed transfer areas relatively quickly and for many species. If we assume that adaptive genetic variation within species is associated with the kind of environmental conditions that define provisional seed zones, it is logical to use these zones as broad indicators of among-population adaptive variation in species. For example, a species that extends across more seed zones is likely to encompass more genetic variation than a species that occurs in fewer zones. In this webinar, Dr. Kevin M. Potter, Research Associate Professor at North Carolina State University, will describe ways in which provisional seed zones can be used in forest tree conservation assessments. One project categorizes and prioritizes species based on threats to their adaptive genetic variation. Another addresses the USDA Forest Service’s requirement under the Montréal Process sustainability reporting agreement to estimate the number and geographic distribution of forest-associated species at risk of losing genetic variation and locally adapted genotypes.