ALFRESCO: Alaska Frame-Based Ecosystem Code

ALFRESCO is a frame-based, spatially explicit model that shows spatial processes of fire and recruitment across Alaska and Western Canada. It combines disturbance events, seed dispersal, and succession on a landscape at a spatio-temporal scale appropriate for investigating effects of climatic change.

A frame-based model partitions temporal changes in vegetation into states or frames. Each frame runs as an independent submodel, simulating processes important to a particular frame and which may cause a switch to a different frame. Variables (drivers) include:

  • climate (growing-season temperature and precipitation)
  • disturbance (fire)
  • seed dispersal

ALFRESCO is based on the idea that vegetation state can be explained using probabilistic—or subject to chance—rules that respond to the model drivers of disturbance and climate. The model assumptions reflect a supposition that fire regime and climate are the primary drivers of landscape-level changes in the distribution of vegetation in this landscape. Learn more about SNAP's work with the ALFRESCO model in habitat research.

ALFRESCO operational details

ALFRESCO accepts SNAP climate data to project impacts of changing climate on fire regimes. It operates year-to-year in a landscape composed of 1 km × 1 km pixels (appropriate for communicating with mesoscale climate and carbon models). It uses vegetation types that simulate the complex mosaic typical of the Far North:

  • Forest: black spruce, white spruce, deciduous
  • Tundra: shrub, graminoid, wetland
  • Barren lichen-moss
  • Temperate rainforest


  • Rupp TS, Starfield AM, Chapin FSI, Duffy P. 2002. Modeling the impact of black spruce on the fire regime of Alaskan boreal forest. Climate Change 55:213–233.
  • Rupp TS, Starfield AM, Chapin FS III. 2000. A frame-based spatially explicit model of subarctic vegetation response to climatic change: comparison with a point model. Landscape Ecology 15:383–400.
  • Yuan, F-M, Yi S-H, McGuire AD, Johnson KD, Liang J-J, Harden JW, Kasischke E, Kurz WA. 2012. Assessment of historical boreal forest carbon dynamics in the Yukon River Basin: Relative roles of climate warming and fire regime changes. Ecological Applications 22:2091-2109.