We’ve got something to prove(nance)
Written by Bethany Bradley, edited by Eve Beaury
Summary
Restoration projects may plant native seeds to restore vegetation composition to what it was like prior to loss from invasion or other disturbance. Seed provenance, or the locations where seeds are sourced, can affect the adaptability and resilience of restored habitat to future environmental changes like climate change. Prober et al. (2015) outline five options for seed provenancing and recommend climate-adjusted provenancing. Climate-adjusted provenancing uses seeds that are sourced both locally and from further away in the direction of expected climate change. The goal of this approach is to increase adaptive capacity in the genetics of the restored population such that it will be more resilient to climate change. Given that the direction of climate change (e.g., warmer and wetter in Massachusetts) is reasonably well known, but the magnitude of climate change (e.g., warmer by how much?) remains uncertain, climate-adjusted provenancing aims to restore with seeds from populations adapted to a range of potential future climate conditions.
Take home points
Prober et al. (2016) outline the following five types of seed provenancing for restoration (presented in Figure 1):
Local provenancing - seeds are sourced from as close as possible to the restoration site. This approach is only recommended if the environment is stable and the local population is well adapted to unique local conditions
Composite provenancing - most seeds are sourced locally, but some seeds are sourced from further away in all directions. This approach is recommended when some environmental change is expected, but the direction of environmental change is unknown. Composite provenancing aims to enhance natural gene flow.
Admixture provenancing - seeds are sourced both locally and further away in all directions in similar quantities. This approach is recommended when a lot of environmental change is expected, but the direction of environmental change is unknown.
Predictive provenancing - seeds are sourced only from further away in the direction of expected environmental change. This approach is recommended when the direction and magnitude of change (e.g., climate change) is well known.
Climate-adjusted provenancing - seeds are sourced both locally and further away in the direction of expected environmental change. This approach is recommended when the direction of change (e.g., climate change) is well known, but the magnitude is less certain.
Management implications
Local provenancing of seeds is an effective approach when the environment is unchanging AND the local population is well adapted to the local conditions (most likely when there is a large local population with high genetic diversity)
Climate adjusted provenancing of seeds is likely to increase adaptation potential given that climate is changing
Admixture provenancing could also be a suitable approach if there is high uncertainty in how the climate is changing in your area
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Keywords: Climate-smart restoration, assisted migration, assisted gene flow, climate adjusted provenancing, forest, managed relocation, plants, restoration