Sourcing the seeds of the future
Vitt, P., J. Finch, R.S. Barak, A. Braum, S. Frischie, and I. Redlinski. 2022. Seed sourcing strategies for ecological restoration under climate change: A review of the current literature. Frontiers in Conservation Science 3: 1-16. PDF.
Written by Audrey Barker Plotkin, edited by Sarah Bois
Summary
Climate change challenges the ‘local is best’ seed source paradigm for restoration projects, but empirical evidence is lacking to guide climate-smart seed sourcing. This comprehensive literature review illuminates the state of knowledge for provenance testing of plant taxa, identifies research biases and gaps, and articulates research needs and practical tools to advance knowledge and practice. The authors compiled results from 176 experimental studies that evaluated how seed provenance affects plant performance in different climates. These studies were biased toward tree species, North American and European forests, and vegetative traits. Most of the experiments assessed how propagule origin influences performance across both climatic and/or geographic distance. Metrics of performance were most often related to survivorship and growth, with few studies assessing fecundity. With the exception of commonly studied trees, insufficient information currently exists to provide general guidance for climate-smart seed sourcing, and – as Clark et al. 2022 showed – even for trees, seedling sources and provenance information is insufficient for large-scale restoration projects. Future work can fill this gap by improving information on seed origin, applying species distribution modeling to seed sourcing decisions, supporting regional seed networks, embedding research in real-world restoration projects, funding long-term studies that allow evaluation of reproductive traits and climate variability, and sharing results via restoration databases.
Take home points
The current literature has strong life-form (trees) and geographic (North American and European forests) biases; prioritizing work on non-tree ‘workhorse’ restoration species and underrepresented geographies will advance climate-smart seed sourcing more equitably
Most response variables focus on vegetative traits; prioritizing new work that assesses fecundity would address the long-term restoration goal of establishing self-sustaining populations of a community of species that is resilient over time
Management implications
Coordination to establish a common set of parameters to evaluate plant performance across climate gradients would provide the foundation to discern generalizable patterns across taxa and geographies
Collaborative work between researchers and practitioners can bridge the gap between the research regarding how plants respond to climate change and the practice of sourcing seed for restoration
Related papers: Clark et al. 2022
Keywords: Climate-smart restoration and assisted migration, literature review