Climate adaptation and ecological restoration in eucalypts

Abstract

Eucalypts are the cornerstone of ecological restoration efforts across the highly modified agricultural landscapes of southern Australia. \u27Local provenancing\u27 is the established strategy for sourcing germplasm for ecological restoration plantings, yet this approach gives little consideration to the persistence of these plantings under future climates. This paper provides a synopsis of recent and ongoing research that the authors are undertaking on climate adaptation in eucalypts, combining new genomic approaches with ecophysiological evidence from provenance trials. These studies explore how adaptive diversity is distributed within and among populations, whether populations are buffered against change through capacity for phenotypic plasticity, and how this informs provenancing strategies. Results to date suggest that eucalypts have some capacity to respond to future environmental instability through adaptive phenotypic plasticity or selection of putatively adaptive alleles. Despite this, growing evidence suggests that eucalypts will still be vulnerable to change. Provenancing strategies that exploit adaptations found in non-local provenances could thus confer greater climate-resilience in ecological restoration plantings, although they will also need to account for potential interactions between climate adaptations and other factors (e.g. cryptic evolutionary variation, non-climate-related adaptations, herbivory and elevated CO2)

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

“…However, we found no evidence that the local provenances of either species were maladapted despite the growing period tested being consistently warmer than average (MAT was 0.43°C and MAP was 9.7 mm above the contemporary [1976–2005] average; unpublished data). This is consistent with the local‐is‐best scenario (Bucharova et al ), although this is not the case in a nearby study site involving an endemic eucalypt species E. gunnii where translocated lower‐altitude provenance performed better than the local (Prober et al ). If translocations for future climates (e.g.…”

Conservation practitioners’ understanding of how to manage evolutionary processes

“…Prober et al. () demonstrated >80% survival of seeds sourced from sites 90 km apart with a 360‐m difference in elevation. The same research shows that the performance of the nonlocal provenance was significantly better in the long term; after 35 years, the survival rate was higher for nonlocal than local seeds (Prober et al.…”

“…Data related to these management problems demonstrate the benefits of changing commonly used management practices (e.g., Prober et al. ; Weeks et al. ), and decision‐support tools are available to guide management decisions (e.g., Byrne et al.…”

Going nowhere fast: a review of seed dispersal in eucalypts

“…Trials outside Australia have demonstrated that many eucalypt species have climatic adaptability beyond that indicated by conventional analyses of their natural distributions (Booth et al 2015). The analyses of González-Orozco et al (2016) endeavoured to assess some of this adaptability, and Prober et al (2016) reviewed recent studies of the climatic adaptability of eucalypts. However, more research is needed to determine the degree to which eucalypt species can rely on this adaptability as well as the existence of suitable refugia to cope with climate change, and the extent to which they will have to depend on their limited dispersal capabilities.…”