A Model To Predict Nutrient Release From Permafrost Under Different Climate Warming Scenarios

Continued warming of the arctic tundra in northern Alaska will have important ecological implications for freshwater ecosystems. An increased active layer depth can lead to nutrient release from permafrost, which may affect the global carbon balance. Comparisons of water quality parameters from the 1970s and 2008-09 from tundra ponds in Barrow, Alaska indicated an increase in water column phosphorus, nitrogen and algal biomass over the past 40 years.

            We designed an incubation experiment to look at nutrient release rates from permafrost cores under different warming scenarios. Permafrost core incubations showed a significant increase in phosphorus and nitrogen concentrations with warming; nitrogen was the dominant nutrient released. There was a temperature dependant threshold between 13°C and 16°C at which a significantly greater nutrient release was observed. Understanding the temperature dependant release of nutrients via permafrost degradation will help to create a predictive model for future additions of nutrients into the Arctic tundra pond ecosystems due to climate warming.