Geographic gradients of net primary production of birch forests of Eurasia

Abstract

When using the compiled database on net primary production (NPP) and biomass of Betula L. genus of Eurasia, transcontinental regularities of changing NPP of wood story from the North to the South according to the bell-shaped curve with a maximum in the subzone of before-forest-steppe are stated, while the NPP of roots and forest understory increases monotonically within the total zonal gradient. In the direction from the Atlantic and Pacific coasts to the continentality pole in Siberia, NPP of stems, branches and all the above-ground part decreases, while NPP of foliage, roots and understory increases. Thus, wood story NPP decreasing offsets by understory one increasing, and vice versa. Productivity of birch foliage, expressed by the ratio of above-ground NPP to foliage one, declines as growth conditions make worse both in the direction of ocean shores to the continentality pole and in direction from the optimal conditions for birch forest growth in the subzone of before-forest-steppe to pessimal conditions both of the tundra in the North and of the Himalayan mountains in the South. © 2015, Pleiades Publishing, Ltd.