Trend in Arctic biomass was calculated from a linear regression of biomass values for all years 1982-2010 (Epstein et al 2012). Pixels with significant trends (p < 0.05) were retained. Biomass was calculated from the relationship between AVHRR NDVI and ground sampling of biomass, as described below: Aboveground phytomass was sampled on transects along the Arctic bioclimate gradient in North America (1750 km long, 8 locations sampled 2003–2006) and Eurasia (1500 km, 5 locations sampled 2007–2010). The study locations were chosen to represent each of the five Arctic bioclimate subzones as displayed on the Circumpolar Arctic Vegetation Map (CAVM) – from Subzone A in the north where shrubs are absent, mosses and lichens are dominant, and bare ground is common, to Subzone E in the south which is characterized by complete ground cover and abundant dwarf shrubs (Circumpolar Arctic Vegetation Map (CAVM) Team 2003). The relationship between landscape-level zonal phytomass sampled along the Arctic transects and satellite NDVI values were compared using logarithmic regression (y = 0.383 Inx + 0.994,R2 = 0.94, p < 0.001).
Back to Circumpolar Arctic Vegetation Map
Map Themes:
AVHRR Biomass 2010, AVHRR Biomass Trend 1982-2010, AVHRR False Color-Infrared 1993-1995, AVHRR NDVI 1993-1995, AVHRR NDVI Trend 1982-2010, AVHRR Summer Warmth Index 1982-2003, Bioclimate Subzone, Coastline and Treeline, Elevation, Floristic Provinces, Lake Cover, Landscape, Landscape Age,
Substrate pH, Vegetation Layer
References
Epstein, H. E., M. K. Raynolds, D. A. Walker, U. S. Bhatt, C. J. Tucker, and J. E. Pinzon. 2012. Dynamics of aboveground phytomass of the circumpolar arctic tundra during the past three decades. Environmental Research Letters 7:015506 (015512 pp).
