Oral Paper

         Ecology

Investigating the eco-evolutionary causes and consequences of plant species rarity with meta-analyses

Presenting Author
Jennifer Boyd
Description
The enduring question of why some species are rare while others are common has important implications for ecological theory, rare species conservation, and overall biodiversity. We used a phylogenetically controlled meta-analysis to investigate eco-evolutionary factors that could influence existing patterns of rarity and elucide the vulnerability of rare species to rapid rates of contemporary environmental change. Specifically, we compared the population genetic diversity, fitness, functional traits, and/or mating systems of 252 rare and 267 common congeneric plant species reported in 154 peer-reviewed articles published from 1978 to 2022. Our findings revealed that rare plant pecies have reduced population genetic diversity, depressed fitness, and smaller reproductive structures than common congeners and that rare species also could suffer from inbreeding depression and reduced fertilization efficiency. These characteristics may constrain the current abundances, distributions, and/or habitat associations of rare species and suggest that rare species may have reduced capacity for adaptation and migration in the face of environmental change. Our meta-analysis was complicated by the various ways in which rarity can be defined, and we recommend that future studies include more nuanced descriptions of species rarity that could facilitate comparisons and syntheses. We also recommend future studies that include ecologically relevant treatments, such as reciprocal transplant experiments, and quantitative genetic and poopulation genomic analyses. Collectively, such research could improve our understanding of the factors that contribute to rarity and allow for predictions of how rare species are likely to respond to environmental change.