Normalized difference vegetation index (NDVI) derived from AVHRR and MODIS satellitesensors is summarized in five northern Alaskan National Park Service units dominated by arctictundra. NDVI is an index of vegetation productivity that is closely related to the warmth ofsummer growing seasons in the arctic. Mean NDVI for ecological sections (broad landscapescalemapping units) is highest for densely vegetated lowlands, lowest in sparsely vegetated highmountain areas, and intermediate in lowlands with significant area of lakes. NDVI during greenup(June) varies 20 to 40% between years, while peak NDVI and late-season NDVI vary 10 to20% between years. These short-term variations are closely linked to current-year variations ingrowing-season [...]
