The paper presents first results of a pan-boreal scale land cover harmonization and classification. A methodology is presented that combines global and regional vegetation datasets to extract percentage cover information for different vegetation physiognomy and barren for the pan-arctic region within the ESA Data User Element Permafrost. Based on the legend description of each land cover product the datasets are harmonized into four LCCS (Land Cover Classification System) classifiers which are linked to the MODIS Vegetation Continuous Field (VCF) product. Harmonized land cover and Vegetation Continuous Fields products are combined to derive a best estimate of percentage cover information for trees, shrubs, herbaceous and barren areas for Russia. Future work will concentrate on the expansion of the developed methodology to the pan-arctic scale.Since the vegetation builds an isolation layer, which protects the permafrost from heat and cold temperatures, a degradation of this layer due to fire strongly influences the frozen conditions in the soil. Fire is an important disturbance factor which affects vast processes and dynamics in ecosystems (e.g. biomass, biodiversity, hydrology, etc.). Especially in North Eurasia the fire occupancy has dramatically increased in the last 50 years and has doubled in the 1990s with respect to the last five decades. A comparison of global and regional fire products has shown discrepancies between the amounts of burn scars detected by different algorithms and satellite data.

In the high northern latitudes the vegetation cover and land surface structure is affected by seasonal freeze/thaw dynamics of the uppermost permafrost layer (active layer). The land cover in the arctic regions is characterized by low vegetation species (shrubs, grasses, mosses) in the northernmost regions as well as the boreal forest in the southern parts.The pan-arctic data product presented here is based on user requirements which were defined in the ESA DUE Permafrost for the coarse resolution vegetation observation variable. The user requirements have shown the need of percentage cover information for different vegetation physiognomy and barren areas. Therefore, fractional cover information for trees, shrubs, herbaceous and non-vegetated areas were extracted using coarse resolution global land cover products in a harmonization approach (Urban et al. 2010).As input MODIS Land Cover, GlobCover, Synmap as well as MODIS VCF (Vegetation Continuous Fields) were used. In the harmonization approach percentage cover values for different vegetation physiognomy and barren areas were extracted using the class description of each land cover legend. Therefore it was feasible to convert thematic classes to fraction cover values for each pixel. The fractional vegetation cover product has a spatial resolution of 1 km. As this dataset provides percentage information instead of thematic classes, a reduction of the spatial resolution for the integration in modeling approaches (spatial resolution 25 km or 0.5°) is feasible (Urban et al. 2010).See "other version" for an updated version 2 of dataset.

Supplement to: Urban, Marcel; Hese, Sören; Herold, Martin; Pöcking, Stefan; Schmullius, Christiane C (2010): Pan-Arctic land cover mapping and fire assessment for the ESA Data User Element Permafrost. Photogrammetrie Fernerkundung Geoinformation, 4, 283-293