Responses to climate change – insights and limitations from herbaceous plant model systems

Herbaceous plant species have been the focus of extensive, long-term research into climate change responses, but there has been little effort to synthesize results and predicted outlooks from different model species. We summarize research on climate change responses for eight intensively-studied herbaceous plant species. We establish generalities across species, examine limitations, interrogate biases, and propose a path forward. All six forb species exhibit reduced fitness, maladaptation, and/or population declines in at least part of the range. Plasticity alone is likely not sufficient to allow adjustment to shifting climates. Most model species also have spatially-restricted dispersal that may limit genetic and evolutionary rescue. These results are surprising, given that these species are widespread, span large elevation ranges, and generally have substantial levels of genetic and phenotypic variation. The focal species have diverse life histories, reproductive strategies, and habitats, but most are native to North America. Thus, these species may poorly represent rare species, habitat specialists, or species endemic to other parts of the world. We encourage researchers to design demographic and field experiments that evaluate plant traits and fitness in contemporary and potential future conditions across the full life cycle, and that consider the effects of climate change on biotic interactions.