No evidence for warming effects on tallgrass prairie plant extirpation in Kalamazoo Michigan

Title: No evidence for warming effects on tallgrass prairie plant extirpation in Kalamazoo Michigan Author list: Emily Horner, Meredith Zettlemoyer Abstract: 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 extinction originates from declines in vital rates such as survival, growth, and reproduction. One way to examine how warming affects local extinctions is to compare responses between locally extinct (or “extirpated”) versus still present (or “extant”) species. In this comparative framework, more negative effects of warming on extirpated species’ vital rates would suggest a role of warming in their local extinction. Extirpated species could also have generally lower vital rates than the 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. We detect general differences in performance between locally extinct vs. extant species. Specifically, small extirpated species have higher survival and are more likely to produce flowers than small extant species. Meanwhile, taller extant species have higher survival and are more likely to produce flowers than tall extirpated species. However, we found that locally extinct and extant species have no general differences in flower or seed production. This result suggests that extirpated species might invest more resources early in life and points to a key difference between extirpated and extant species that contributes to our limited understanding of the population dynamics of local extinction.