Seed sourcing for longleaf pine ground cover restoration: using plant performance to assess seed transfer zones and home‐site advantage

Abstract

Seed sourcing is a concern for restoration practitioners in all regions and habitats. The possibility that plants are most suited to their home environments due to genetic adaptations to local biotic and abiotic conditions prompts questions of how far plant material can be moved from home sites and remain ecologically appropriate in a restoration setting. We tested a suite of provisional seed transfer zones at multiple geographic scales to assess their ability to capture potentially adaptive genetic variability among populations in the southeastern United States. Furthermore, we examined the effects of seed source and phenotypic plasticity on plant performance and whether locally sourced individuals have adaptive advantages relative to more distantly sourced individuals. With a reciprocal transplant and a common garden study, we show that, although seed source is the best predictor of differentiation in plant performance, performance differences among populations across larger seed transfer zones within the longleaf pine ecosystem are relatively minor. These findings suggest that consideration of larger seed zones within the longleaf pine ecosystem that are also more logistically and economically viable is warranted. However, earlier flowering of individuals from seed sourced outside the longleaf pine ecosystem suggests that moving plant material greater distances is more likely to result in phenological mismatches between plants and pollinators. Species‐specific differences, however, indicate there is insufficient evidence to support a recommendation for a single set of seed transfer zones within the southeastern United States for all species.