Phenotypic plasticity and genetic diversity elucidate rarity and vulnerability of an endangered riparian plant
Boyd, Jennifer et al. (2021), Phenotypic plasticity and genetic diversity elucidate rarity and vulnerability of an endangered riparian plant, Dryad, Dataset, https://doi.org/10.5061/dryad.2v6wwpzmv
Anthropogenic environmental change threatens many species and can be especially challenging for rare species given their potentially limited capacity for migration and adaptation relative to more common species. The ability to acclimate via phenotypic plasticity could provide an important path to persistence, especially for rare species. We investigated the responses of an endangered plant species endemic to a highly dynamic riparian habitat in southeastern Tennessee, USA, and its most widespread congener to environmental change to elucidate their current statuses and future vulnerability. Specifically, we compared the population- and species-level plasticity of rare Pityopsis ruthii and common P. graminifolia to contrasting light, temperature, and water conditions in a growth chamber experiment to evaluate their potential to acclimate to environmental change. Contrary to our expectations, P. ruthii had greater phenotypic plasticity than its common congener in response to both altered light and water availability. But this plasticity was not associated with increased fitness, suggesting that it was not adaptive. Concurrently, we genotyped these individuals at nine putatively neutral microsatellite loci to contrast genetic diversity across the range of each species. As expected, P. ruthii exhibited reduced genetic diversity relative to its more common congener. Overall, our findings accord with the narrow range and current habitat specificity of P. ruthii, especially its tolerance of highly variable water, and highlight its potential vulnerability to future environmental change.
National Science Foundation, Award: 1655762
National Science Foundation, Award: 1655521
National Science Foundation, Award: 1655732