Intraspecific functional trait structure of restoration‐relevant species: Implications for restoration seed sourcing

Abstract

1. Recent research has highlighted the existence of significant intraspecific trait variation within and among populations of plant species. This inherent variation within species means there is a wealth of trait diversity from which to source germplasm for use in ecological restoration. However, it remains unclear how to source materials from this pool of trait diversity in order to achieve desired outcomes and support ecosystem function in a restoration context. 2.We provide a framework to study the structure of trait variation across populations and genotypes in an effort to bridge functional trait research with the sourcing of native plant materials for restoration. We investigated the structure of intraspecific functional trait variation in three forb species used in restoration on the Colorado Plateau to (a) understand the structure of functional trait variation within and among populations, and (b) determine if individual and multivariate functional traits differ between populations while accounting for trait variation within and among genotypes.3. We found considerable functional trait variation at all sampling levels, with variation within populations often surpassing variation among populations. Still, we observed population-level differences in trait values in 8 of the 12 species-by-trait combinations and populations largely segregated in multivariate trait space. 4. Synthesis and applications. Using micropropagation techniques, we uncovered population-level differences in functional trait variation, suggesting that mixing populations to create restoration germplasm following a regional admixture provenancing approach could lead to increased functional diversity in restorations. However, the substantial trait variation identified within some populations of our study species also suggests a similar potential when utilizing genotypically diverse material from even a single population. Further research on these and other species is needed to understand the structure of intraspecific functional trait variation and how it impacts ecosystem function. The approach outlined in this study can assist researchers in assessing the underlying trait variation present in various restoration materials and provide managers with more detailed information that can help make germplasm sourcing decisions. K E Y W O R D SColorado Plateau, germplasm, intraspecific trait variation, micropropagation, plant functional traits, regional admixture provenancing, restoration, seed sourcing | 865Journal of Applied Ecology ZELDIN Et aL. S U PP O RTI N G I N FO R M ATI O NAdditional supporting information may be found online in the Supporting Information section. How to cite this article: Zeldin J, Lichtenberger TM, Foxx AJ, Webb Williams E, Kramer AT. Intraspecific functional trait structure of restoration-relevant species: Implications for restoration seed sourcing. J Appl Ecol. 2020;57:864-874.

Need to Seed? Ecological, Genetic, and Evolutionary Keys to Seed-Based Wetland Restoration

“…Seeding also allows for the inclusion of higher numbers of species and genotypes relative to the more logistically intensive planting process (Godefroid et al, 2011;Reynolds et al, 2012). Higher genetic diversity is critical for the ability of plants to evolve in response to future changes, and both genetic and species diversity are essential to support ecosystem multifunctionality (section "Seed Source Diversity"), i.e., the simultaneous support of multiple ecosystem functions (Bischoff et al, 2010;Reynolds et al, 2012;Kettenring et al, 2014;Palma and Laurance, 2015;Espeland et al, 2017;Zeldin et al, 2020).…”

“…Populations sampled should span a range of local to non-local sources across a region for a "regional admixture provenancing" approach (sensu Bucharova et al, 2019) unless there is strong evidence for outbreeding potential and maladaptation to drive a more conservative local-sourcing approach. On the contrary, many wetlands are in highly altered landscapes with substantial fragmentation, where the available seed may be of poor quality due to inbreeding or genetic drift in remaining remnant wetlands (Broadhurst et al, 2008;Borders et al, 2011;Jordan et al, 2019); thus regional admixture provenancing to increase genetic diversity and phenotypic plasticity in seed mixes would be appropriate especially as a "biological insurance" to extreme and fluctuating environments and to foster adaptive potential in the face of climate change (Hughes and Stachowicz, 2004;Reusch et al, 2005;Broadhurst et al, 2016;Zeldin et al, 2020). These recommendations for regional admixture provenancing are also consistent with the broad dispersal (section "Site and Landscape Context") and gene flow patterns of many avian-dispersed wetland species (Orsenigo et al, 2017;Kettenring et al, 2019b).…”

Phylogenetically and functionally diverse species mixes beget diverse experimental prairies, whether from seeds or plugs

“…Moreover, weeds were mostly controlled manually rather than chemically as is typical, with the exception of an annual, early‐spring spot‐treatment of emerging Cirsium . Finally, we had one source of seeds and plant material per species and thus little intraspecific diversity and associated potential benefits for restoration outcomes and climate resilience (Khalil et al 2019; Zeldin et al 2020). We did not design our experiment to evaluate the importance to restoration of mixing populations for climate resilience or other factors (e.g.…”

Using Genomic Selection to Develop Performance-Based Restoration Plant Materials

“…Whitham [ 3 ] lamented the lack of good plant-material options for populations compromised at the warm end of species’ distributions. Furthermore, seed-transfer options may be limited due to the emergence of no-analog ecosystems as a response to climate change [ 139 , 140 , 141 , 142 ]. A justification for developing more effective native plant materials can be made on this basis.…”