Seed Germination for Restoration in a Challenging Species

Abstract

Development projects that impact Arctostaphylos morroensis (Morro manzanita), a federally listed threatened species, typically require habitat restoration, mitigation or both. Replacement plantings for habitat restoration and mitigation can be obtained by establishing new plants from cuttings or seed propagation. Propagation of A. morroensis from seed has the advantage of increasing genetic diversity but typically has low germination rates. We investigated various propagation techniques with the goal of determining the most efficient and effective approach for generating A. morroensis from seeds in a greenhouse setting. We compared emergence rates for fruits from two sources, shrubs and leaf litter; examined germination in response to various scarification treatments including fire, heat, acidification, and no treatment; and compared germination in response to stratification, including cold and warm storage. We found that shrub-sourced fruits, and acidification and fire (gas torch) scarification yielded the best results. We also found that a warm stratification period worked best for shrub-sourced fruits and a cold stratification period worked best for litter-sourced fruits. Identifying the most efficient propagation methods can increase success and decrease costs associated with restoring and establishing healthy A. morroensis communities, and serve as a potential model for use in other manzanita species.