From temperate rainforests to arctic tundra, a wealth of ecosystems span the vast and varied landscapes of Alaska. Among these are rare ecosystems, which support unique assemblages of specialized and/or diverse flora and fauna within a small geographic area or restricted range. In Alaska, remoteness preserves many ecosystems in pristine condition, yet some naturally-uncommon systems are in decline due to their intrinsic vulnerabilities or external threats.

Here we provide descriptions, distribution maps, and conservation status assessments for rare ecosystems in Alaska. Ecosystems are described at two levels – the Biophysical Setting and the Plant Association. Biophysical settings represent the vegetation that dominates the landscape in the absence of human action for a specific physical environment and natural disturbance regime, whereas plant associations are a finer-scale type representing communities of definite floristic composition and uniform habitat.