Multi‐century stasis in C3 and C4 grass distributions across the contiguous United States since the industrial revolution

摘要: Aims Understanding the functional response of ecosystems to past global change is crucial predicting performance in future environments. One sensitive and functionally significant attribute grassland percentage species that use C4 versus C3 photosynthetic pathway. Grasses using pathways are expected have different responses many aspects anthropogenic environmental followed industrial revolution, including increases temperature atmospheric CO2, changes land management fire regimes, precipitation seasonality, nitrogen deposition. In spite dramatic over 300 years, it unknown if grass grasslands has shifted. Location Contiguous United States America. Methods Here, we used stable carbon isotope data (i.e. δ13C) from 30 years soil samples, as well herbivore tissues date 1739 CE, reconstruct coarse-grain composition North American sites compare with modern vegetation. We spatially resampled these three datasets a shared 100-km grid, allowing comparison δ13C values at resolution extent common for climate model outputs biogeographical studies. Results At this spatial grain, bison tissue proxy was superior because soils reflect integration local inputs, whereas sample vegetation across landscapes. Bison indicate historical photosynthetic-type similar vegetation. Main conclusions Despite major change, comparing plot centuries revealed distribution grasses not changed significantly since 1700s. This particularly surprising given CO2 fertilization grasses. Our findings highlight critical importance capturing full range physiological, ecological demographical processes biosphere models climates ecosystems.