Provisional seed zones for native plants

Deploying vigorous, well adapted, and ecologically appropriate plant materials is a core component of a successful restoration project. The key to identifying appropriate plant materials (e.g. seeds) lies in understanding the genetics of adaptation through common garden studies or reciprocal transplant experiments. However, restoration practitioners are frequently required to make seed collection and deployment decisions for species and landscapes which lack seed zones and transfer guidelines established through genetic research. So what are practitioners to do when no seed transfer guidelines exist for a species of interest? One approach for choosing germplasm in the absence of genetic information is to try and match the seed source and planting site conditions as closely as possible. Our provisional seed zone model provides a powerful decision support tool for characterizing site conditions and choosing plant material sources that originate from similar environments. The model integrates climate factors that are known to affect plant survival and growth (temperature and precipitation) and ecological factors. It builds on earlier efforts such as USDA plant hardiness zones (Cathy 1990, www.arborday.org) and “Plant Adaptation Regions” (PARs, Vogel et al. 2005). The provisional zones can be utilized to guide movement of plant material until species specific information becomes available via genetic research studies on adaptive traits.