Advancing plant phenology and reduced herbivore production in a terrestrial system associated with sea ice decline

The contribution of declining Arctic sea ice to warming in the region through Arctic amplification suggests that sea ice decline has the potential to influence ecological dynamics in terrestrial Arctic systems. Empirical evidence for such effects is limited, however, particularly at the local population and community levels. Here we identify an Arctic sea ice signal in the annual timing of vegetation emergence at an inland tundra system in West Greenland. According to the time series analyses presented here, an ongoing advance in plant phenology at this site is attributable to the accelerating decline in Arctic sea ice, and contributes to declining large herbivore reproductive performance via trophic mismatch. Arctic-wide sea ice metrics consistently outperform other regional and local abiotic variables in models characterizing these dynamics, implicating large-scale Arctic sea ice decline as a potentially important, albeit indirect, contributor to local-scale ecological dynamics on land. The effect of lower Arctic sea ice levels on local terrestrial ecosystems is not well studied. Here Kerby and Post find that decreasing Arctic sea ice levels are associated with the early emergence of plant growth, which decouples plant growth from the birth of Caribou calves, and may be associated with increased calf mortality.