Mammal communities of primeval forests as sentinels of global change

Understanding the drivers and consequences of global environmental change is crucial to inform predictions of effects on ecosystems. We used the mammal community of Białowieża Forest, the last lowland near-primeval forest in temperate Europe, as a sentinel of global change. We analyzed changes in stable carbon (δ13C) and nitrogen (δ15N) isotope values of hair in 687 specimens from 50 mammal species across seven decades (1946–2011). We classified mammals into four taxonomic-dietary groups (herbivores, carnivores, insectivores, bats). We found a significant negative trend in hair δ15N for the mammal community, particularly strong for herbivores. This trend is consistent with temporal patterns in nitrogen deposition from (15N depleted) industrial fertilizers and fossil fuel emissions. It is also in line with global-scale declines in δ15N  reported in forests and other unfertilized, non-urban terrestrial ecosystems and with local decreases in N foliar concentrations. The global depletion of...