No evidence for warming-driven extirpation of tallgrass prairie plants

More and more species face extinction as our climate warms. Understanding how climate change influences local extinctions may help us comprehend and predict global extinctions. Ultimately, local extinctions stem from declines in vital rates such as survival, growth, and reproduction. One way to examine how warming might have affected local extinctions is to compare responses between locally extinct versus extant (still present) species. In this comparative framework, more negative effects of warming on locally extinct species’ (but not extant species’) vital rates would suggest a role of warming in their local extinction. We also expect that locally extinct species would have generally lower vital rates than more successful extant species, regardless of warming. We used an experimental heating array to compare extant and reintroduced locally extinct tallgrass prairie species’ vital rates under ambient vs. warmed (+3°C) conditions. Warming does not affect the vital rates of these tallgrass prairie plants, suggesting that warming is not a major reason that these species went locally extinct in Kalamazoo County, Michigan, nor is it a major threat to the extant species studied here. We detect general differences in performance between locally extinct vs. extant species. Specifically, taller extant species have higher survival, growth rates, and probability of flowering than tall locally extinct species. This result points to a key demographic difference between locally extinct and extant species that contributes to our limited understanding of the population dynamics of local extinction.