Introduction

Abstract

The general distribution of the plant and animal communities can be explained in terms of 4 master factors: climate (insolation and air-temp.), soil, manuring by sea-birds, and water-supply. The climatic gradient produced by the meeting of the Polar ice-pack with the Gulf Stream causes corresponding gradients in (1) the types of vegetation[long dash]a gradient divisible naturally into 4 zones: Barren zone, Dryas zone, Cassiope zone, and the inner fjord or Empetrum zone; (2) the communities of land-animals; and (3) the intertidal fauna. By combining all these lines of evidence, a provisional map is constructed showing the main life-zones for the whole of the Spitzbergen archipelago. These zones can be traced on a much broader scale across Greenland and arctic Canada, and in the mountains of northern Scandinavia; and they demonstrate the very high-arctic character of Spitzbergen communities. The gradient outlined above is interfered with by bird-manuring, which produces distinctive (and usually grassy) communities even in the most barren parts of Spitzbergen. The effects of bird-manuring on animals and plants were studied intensively in several cases.