Flexible Seed Harvest: Revisiting the 10% Rule

Seed collection is a vital conservation method used to ensure global food security by maintaining a source of genetic diversity in food crops and prevent the loss of biodiversity from natural or anthropogenic events that cause the extirpation of small populations. The Global Strategy for Plant Conservation facilitates global and national level plant conservation strategies including a target of collecting at least 75% of the threatened plant species in ex-situ collections with at least 20% being available for recovery and restoration. Local participation to reach this goal is facilitated by the Center for Plant Conservation (CPC). However, removing seed from small populations can increase extinction risk for species of conservation concern. Current restrictions on seed harvest meant to limit risk to rare species is based on stochastic simulations of a few perennial species with limited demographic data. Our work examines the universality of this threshold across lifespans (annuals to long-lived perennials). We account for variation in vital rate responses by using many transition matrices and adding predictions of worsening conditions due to climate change and human impacts by simulating different harvesting practices in years with high vs. low seed production.

Michelle DePrenger-Levin, Denver Botanic Gardens; Michael Kunz, North Carolina Botanical Garden; Emily Coffey, Atlanta Botanic Garden; Tom Kaye, Institute for Applied Ecology; Anna Lampei Bucharová, Institute of Landscape Ecology (ILÖK), University of Münster