Illuminance under canopy in different types of forest in the northern taiga

Abstract

Abstract The illumination under the canopy in different types of pine and spruce forests is considered. The research was carried out in different points of the Northern taiga of the Arkhangelsk region. Illumination was measured using a luxmeter in different directions: at the level of the moss-lichen layer, at the level of the grass-shrub layer and at a height of 1.3 m; at different distances from the tree trunk; at different distances from the edge of the forest. Illumination in pine forests at the level of the moss-lichen layer is 2.3 times higher than in spruce forests. Under the canopy of spruce forests, it is 1–3%, and in the pine forests, 3–9% of the illumination in the open. Illumination from tree trunks to the edge increases in pine and spruce forests equally. The lowest illumination is observed at the level of the moss-lichen layer, then it increases to the grass-shrub layer, and then practically does not change. However, the difference between pine and spruce forests is consistently high 47%. The decrease in illumination in the tree stand as it moves away from the edge in blueberry pine forests is observed up to a distance of 10 m from the edge, and in blueberry spruce forests up to 6 m.