Large herbivores limit CO2 uptake and suppress carbon cycle responses to warming in West Greenland

摘要: Changes in the terrestrial carbon cycle may ameliorate or exacerbate future climatic warming. Research on this topic has focused almost exclusively abiotic drivers, whereas biotic factors, including trophic interactions, have received comparatively little attention. We quantified singular and interactive effects of herbivore exclusion simulated warming ecosystem CO2 exchange over two consecutive growing seasons West Greenland. Exclusion caribou muskoxen past 8 years led to dramatic increases shrub cover, leaf area, photosynthesis, a nearly threefold increase net C uptake. These responses were accentuated by warming, but only absence herbivores. Carbon alone combined with driven changes gross as limited differences respiration observed. Our results show that large herbivores can be critical importance mediators arctic climate change.