Impacts of boreal forest fires and post-fire succession on energy budgets and climate

Brendan Morris Rogers, UC Irvine, Dept. of Earth System Science, bmrogers@uci.edu (Presenter)
James T. Randerson, UC Irvine, Dept. of Earth System Science, jranders@uci.edu

Vegetation compositions of boreal forests are largely determined by recovery patterns after large-scale disturbances. These include windthrow, pests and pathogens, and most notably, wildfires. Forest composition exerts a large control on energy and greenhouse gas budgets by influencing albedo, net radiation, turbulent energy fluxes, and carbon stocks. Impacts of boreal forest fires on climate are therefore products of direct fire effects, including charred surfaces and emitted aerosols and greenhouse gasses, and post-fire vegetation succession, which affects carbon and energy exchange for many decades after the initial disturbance. Climate changes are expected to be greatest at high latitudes, leading many to project substantial increases in boreal forest fires, and thus fire-related feedbacks. While numerous studies have documented the effects of post-fire landscape on energy and gas budgets in boreal forests, no continental analysis using a coupled model has been performed. This study will quantify the effects of boreal forest fires and post-fire succession on climate using model experiments in the Community Earth System Model. Model inputs are derived from remote sensing products and national inventories. We use 20th century climate data and MODIS vegetation continuous fields and land cover classes to identify boreal forests across North America and Eurasia. Historical fire return intervals are derived from a regression approach utilizing the Canadian and Alaskan Large Fire Databases, the Global Fire Emissions Database v3, and land cover and climate data. Succession trajectories are derived from the literature and MODIS land cover over known fire scars. Major improvements in model-data comparisons of long-term energy budgets were observed by prescribing post-fire vegetation succession. Global simulations using historical and future burn area scenarios will highlight the potential impacts on climate from changing fire regimes and provide motivation for including vegetation succession in coupled simulations.

Presentation Type:  Poster

Session:  Coupled Processes at Land-Atmosphere-Ocean Interfaces   (Mon 4:00 PM)

Associated Project(s): 

• Randerson, Jim: Global Carbon Emissions from Fires: Improving our Understanding of Interactions between Land Use, Fires, and Climate Change ...details

Poster Location ID: 75