Given the Arctic Amplification of global warming, there is an increased need to understand the impacts of climate change on arctic terrestrial ecosystems. Changes in arctic tundra productivity may result in negative or positive feedbacks to climate change through changes in carbon sequestration. Here we applied the Terrestrial Ecosystem Model with Dynamic Vegetation and Dynamic Organic Soil Layers to five sites along an environmental gradient in northern Alaska to gain a better understanding of how future variations in climate may influence ecosystem productivity along this gradient, considering a range of tundra types. We examined how the net ecosystem productivity along the gradient was influenced by forecasted increases in both precipitation and air temperature from 2010 – 2100.
Results/Conclusions
The model showed significant correlation between precipitation and net ecosystem production and air temperature and net ecosystem production for shrub and wet sedge tundra communities in nearly all of the sites considered. Shrub tundra net ecosystem production showed dependence on precipitation and air temperature across the five sites, with a particular dependence on air temperature. Trends among tussock tundra communities varied, with several communities showing significant correlation between net ecosystem productivity and precipitation or air temperature at various sites. Net primary productivity increased across all sites considered, while heterotrophic respiration did not necessarily increase. Thus the predicted net ecosystem productivity increase would be associated with carbon sequestration in Alaskan arctic tundra through the end of the century as the climate becomes warmer and precipitation increases.