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Understanding the resilience of arctic community assembly and soil C to fire disturbance and nutrient addition

Adrian V. Rocha, Univ of Notre Dame, arocha1@nd.edu (Presenter)
David Medvigy, Univ of Notre Dame, dmedvigy@nd.edu

Fires in the arctic are anticipated to increase in a future warmer world, yet remain poorly understood in terms of their impacts on ecosystem structure and function. The Anaktuvuk River fire was an unprecedented event that occurred in 2008 on the North Slope of Alaska. We present nearly a decade of post-fire recovery of Net Ecosystem Exchange of CO2 fluxes and ecosystem C stocks from Severely- and Un-burned sites located in close proximity to each other. NEE at the Severely burned site recovered within 4 years-aided by the rapid recovery and stimulation of vegetation productivity and a shift to shrub canopies. Soil C and N stocks remain depleted, and as a result, it is hypothesized that the stimulation of vegetation productivity is not sustainable. In 2016, we setup a multifactorial N, P and N+P nutrient addition experiment at the Severely burned and Unburned sites to further understand the role of nutrients in stimulating vegetation productivity and C sequestration. Five blocks of treatments have been fertilized at the beginning of each growing season, and a biomass harvest is planned for summer 2018. We will use these data to parameterize ED2-MEND, which is a vegetation demography model linked to biogeochemistry model of C, N, P. ED2-MEND will help to understand the development and post-fire C stock and flux recovery into the future and decrease the uncertainty regarding the impacts of tundra fires on climate.

Associated Project(s): 

Poster Location ID: 52

Session Assigned: Carbon Dynamics

 


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