Species-tailored sampling guidelines remain an efficient method to conserve genetic diversity ex situ: A study on threatened oaks

• Published in: Biological conservation 2022-11, Vol.275, p.109755, Article 109755
• Main Authors: Rosenberger, Kaylee, Schumacher, Emily, Brown, Alissa, Hoban, Sean
• Format: Article
• Language: English
• Subjects: Botanic garden; Conservation planning; Demography; Ex situ conservation; Molecular ecology; Seed bank; Simulation; Threatened species
• ISSN: 0006-3207; 1873-2917
• DOI: 10.1016/j.biocon.2022.109755

To safeguard species so they can adapt to environmental change, ex situ collections must represent a sufficient amount of species' wild genetic diversity. Because of sampling constraints such as time and cost, conservation biologists have worked to recommend minimum sample sizes that efficiently capture genetic diversity. However, the minimum number of individuals that should be sampled for ex situ collections may vary according to species biogeography, reproductive and dispersal biology, and history. Using simulations, we first aimed to establish minimum sample sizes for 14 IUCN Red List threatened oak species and determine if one minimum sample size can capture the genetic diversity of these closely related species with similar biology and dispersal, but different population sizes and ranges. We found that the answer is no–minimum size ranged from 81 to over 500. Second, we addressed a common concern with simulations–that their predictions may be too dependent on assumptions and may neglect uncertainty. We varied some parameters used for modeling each species in simulations to determine if the minimum sample size changed when this parameter was changed. We determined that the variation in minimum size due to parameter uncertainty was moderate compared to variation due to species' characteristics. Based on this, we propose that simulations may be reliable tools for practical use for many species, even when there is uncertainty in the parameters used for modeling. We conclude that one minimum sample size cannot be recommended to fit all 14 species, but that simulations can help create sampling guidelines tailored to each species. •Minimum sample sizes are essential for conserving species ex situ.•Minimum sample sizes for 14 oak species vary widely, due to geographic distributions.•We found that species-tailored guidelines efficiently capture genetic diversity.•Simulations are reliable tools to model species and are robust to model assumptions.•Simulations are recommended to contribute to conserving species genetic diversity.