Priority Actions to Improve Provenance Decision-Making

Abstract

Selecting the geographic origin-the provenance-of seed is a key decision in restoration. The last decade has seen a vigorous debate on whether to use local or nonlocal seed. The use of local seed has been the preferred approach because it is expected to maintain local adaptation and avoid deleterious population effects (e.g., maladaptation and outbreeding depression). However, the impacts of habitat fragmentation and climate change on plant populations have driven the debate on whether the local-is-best standard needs changing. This debate has largely been theoretical in nature, which hampers provenance decision-making. Here, we detail cross-sector priority actions to improve provenance decision-making, including embedding provenance trials into restoration projects; developing dynamic, evidence-based provenance policies; and establishing stronger research-practitioner collaborations to facilitate the adoption of research outcomes. We discuss how to tackle these priority actions in order to help satisfy the restoration sector's requirement for appropriately provenanced seed.

Stability of species and provenance performance when translocated into different community assemblages

“…The accelerating pace of global climate change requires greater consideration of the planting material used in restoration (Breed et al ). The last decade has seen active debate on the paradigm shift from a traditional “local‐is‐best” scenario (Mortlock ; Bucharova et al ) to strategies that enrich plantings with seed from provenances growing in environments matching predicted future climates (i.e., climate‐adjusted provenancing—Prober et al ).…”

“…In a restoration context, this involves strategies, such as climate‐adjusted provenancing, which aim at enriching local plantings with seed predicted to be genetically adapted to future climates of the planting site (Prober et al ). While a number of technical and practical challenges remain in broadly adopting such strategies (Breed et al ), the extent to which biotic interactions may modify species and provenance performance (Pearse et al ; Gellie et al ) has received little consideration (Whittet et al ; Bucharova ). This is particularly important as species and provenance translocations are not made in isolation but are embedded in diverse and even novel communities.…”

“…This is particularly important as species and provenance translocations are not made in isolation but are embedded in diverse and even novel communities. Indeed, as restoration involves rebuilding functionally and structurally complex ecosystems, the correct choice of species and provenance is key to its success (Breed et al ).…”

Population history provides foundational knowledge for utilizing and developing native plant restoration materials

“…Regardless of the potential intraspecific or interspecific impacts resulting from using nonlocal genotypes in restoration treatments, genetic diversity has been recognized as a unit of conservation concern (see Hoban et al., and references therein), suggesting the maintenance of geographic patterns of genetic variation by avoiding the mixture of local and nonlocal genotypes should be an implicit restoration goal (Bucharova et al., ). Therefore, gathering information on the genetics of native plants important to restoration is imperative for making the appropriate seed sourcing decisions for ecosystem restoration (Breed et al., ).…”

Native seed addition as an effective tool for post-invasion restoration

“…The more suitable alternative could be species-rich seed mixtures produced by threshing of local hay or commercial regional mixtures that are increasingly available throughout Europe and other areas of the world (e.g. (Breed et al, 2018; Bucharova et al, 2019; Kiehl, Kirmer, Shaw, & Tischew, 2014; Mitchley, Jongepierová, & Fajmon, 2012). Another reason for the strong grass dominance may be a high content of available nutrients in the soil.…”