Modeling Post-fire Successional Trajectories Under Climate Change in Black Spruce Forests of Interior Alaska

Alaska boreal forest ecosystems are experiencing greater wildfire frequencies relative to the region's historic fire regime. This increases the probability of short-interval reburning, which may cause shifts in successional trajectories in this ecosystem . To better understand these relationships and examine potential shifts in vegetation composition following short-interval, repeat fires, we used LANDIS-II, a forest landscape model, to simulate changes in tree and shrub composition in response to climate change and increasing fire frequency. We used the Net Ecosystem Carbon & Nitrogen Succession extension to LANDIS-II to simulate forest succession with wildfire under historic and RCP 8.5 climate change scenarios to the year 2100. Landscape parameters were calibrated from field measurements taken from plots within two different sites in interior Alaska, 15 years post-fire and with one, two or three fires having occurred within a 60 year period prior to the most recent fire. Wildfire was calibrated using publicly available historic fire datasets for the region. We will present the results of our simulations over an 11 million hectare study landscape, examining the resulting successional trends, relationships, and feedbacks that may drive potential future shifts in boreal forest composition long-term under an increasing fire frequency regime in interior Alaska.