Combination of herbivore removal and nitrogen deposition increases upland carbon storage.

Ecosystem carbon (C) accrual and storage can be enhanced by removing large herbivores as well as by the fertilizing effect of atmospheric nitrogen (N) deposition. These drivers are unlikely to operate independently, yet their combined effect on aboveground and belowground C storage remains largely unexplored. We sampled inside and outside 19 upland grazing exclosures, established for up to 80 years, across an N deposition gradient (5-24 kg N ha(-1) yr(-1) ) and found that herbivore removal increased aboveground plant C stocks, particularly in moss, shrubs and litter.