Geographical Gradients of Annual Biomass Production from Larch Forests in Northern Eurasia

From the vast collection of published data concerning larch forest biomass in northern Eurasia (390 plots), data from 17 plots selected from seven different regions were analyzed to determine how geographical differences influence the estimates of the annual net production rate. Nine plots were selected from four different regions of Siberia (southern and middle taiga, forest-steppe, forest-tundra), and the other eight plots were selected from three regions; Middle-Europe (Czechoslovakia, 1 plot), the Far East (northern China, 3 plots) and a Japanese Island (4 plots). Annual net production of each component (foliage, stem, branch, root and understory) was estimated separately using a multiple regression model, along with some parameters concerning stand characteristics (stand age, tree density, diameter and height), which had been developed previously for the regions in the Eurasian borea1larch forests. For this estimation, annual net production of each component was primarily assumed to be proportional to foliage biomass. Upon analysis, regional gradients of the estimated productivity from each of the larch forests could be determined. Specifically, the net production rates had increased from the northern (tundra) to the southern (steppe) parts of the Siberian taiga, and had decreased from th