Abstract
Tropical species have been hypothesized to be particularly sensitive to temperature increases because of their physiological specialization to stable climates. Here we use two independent datasets to test whether tropical montane species are tracking recent warming via upslope range shifts better than temperate montane species. First, we compiled published data documenting recent elevational shifts of plants and animals. For this resurvey data, we analyzed temperature tracking for both entire communities (N = 83) and for individual species (N = 2871). Second, we calculated temperature tracking of tree community structure using data from repeatedly surveyed forest inventory plots from mountainous regions of the Americas (N = 300). We defined temperature tracking scores as the ratio of observed changes vs. expected changes based on estimates of local warming. Both datasets show that tropical montane taxa are tracking changing temperatures significantly better than their temperate counterparts. On average, tropical communities are tracking temperature 2.6 times more than temperate communities (0.84 ± 0.15 vs. 0.32 ± 0.074), tropical species are tracking temperature 2.3 times more than temperate species (0.91 ± 0.18 vs. 0.40 ± 0.083), and tropical tree plots are tracking temperature 4.4 times more than temperate tree plots (0.44 ± 0.11 vs. 0.099 ± 0.042). This latitudinal gradient in temperature tracking is consistent with accumulating evidence that tropical montane biotas are disproportionately sensitive to ongoing global warming.
Competing Interest Statement
The authors have declared no competing interest.