A Preliminary Model of Processes Affecting Primary Production in the Arctic Tundra

Abstract

A preliminary model of physical processes affecting primary production in the arctic tundra was developed from the energy budget equation for single leaves, equations expressing the radiation and wind profiles in the canopy, and a simplified concept of the allocation of photosynthetic material to stems and leaves. The model was validated with data for 1965 and 1970 from Point Barrow, Alaska. For both years, calculated net production increased as leaf area increased in spite of decreasing solar radiation through the growing season, except for a drop in net production when temperatures rose in August 1965. Production of Dupontia fischeri was lower in a mixed sward than in a pure sward. Production increased with decreased standing dead material, increased leaf area index, increased solar radiation, and increased air temperatures up to 5 to 10°C Production was not affected by infrared radiation from the sky or from the ground.