This dataset consists of two distinct sets of single-band GeoTIFFs: one representing the modal vegetation type for each computed over a given era, and one representing the occurence percentage of a given vegetation type for a given era. The former is provided in the alfresco_vegetation_mode_statistic.zip archive, and the latter is provided in the alfresco_vegetation_type_percentage.zip archive. Both subdatasets are derived from the same set of ALFRESCO model runs driven by each of the following five models: GFDL-CM3, NCAR-CCSM4, MRI-CGCM3, IPSL-CM5A-LR, and GISS-E2-R. The calculation for each pixel is done over all years within the era and among all the simulations (200 replicate runs x number of years per simulation).

The file naming convention for the modal dataset looks like this: alfresco_relative_vegetation_change_<start year of summary era>-<end year of summary era>_<model>_<scenario>.tif. The convention is identical for the type percentage version, but with an integer code suffix indicating the vegetation type. The mapping for integer value to vegetation type is as follows:

0: not_modeled, 1: black spruce, 2: white spruce, 3: deciduous forest, 4: shrub tundra, 5: graminoid tundra, 6: wetland tundra, 7: barren lichen moss, 8: temperate rainforest

The historical runs of the ALFRESCO outputs, driven by CRU-TS, are also included in this revision.

For background on ALFRESCO, please refer to the following reference:

Daniel H. Mann, T. Scott Rupp, Mark A. Olson, and Paul A. Duffy. 2012. Is Alaska's Boreal Forest Now Crossing a Major Ecological Threshold?

Arctic, Antarctic, and Alpine Research 44 (3), 319-331