Dynamics of Phytomass and Net Primary Production of Russian Forests in 1961-1998: an attempt of aggregated estimation

Aggregated estimates of the dynamics of phytomass and Net Primary Production (NPP) of Russian forests are presented for the period 1961-1998. The calculations for 1990 are based on detailed inventories, using data from the State Forest Account by ecoregions, available results of measurements and reference data on the productivity of forests which have been accumulated in Russia during the last decades. For 1990, the total amount of phytomass in forest ecosystems is estimated to be 66450 Tg (=10^12g) dry matter, or 32862 Tg C. Of the total amount of phytomass carbon, 78.0% of phytomass are above ground (including 6.2% green part and 71.8% woody part) and 22.0% are presented by roots. The NPP is estimated to be 3660 Tg dry matter per year or 1708 Tg C yr^-1. 75.4% of NPP are allocated above ground, and 49.0% of total NPP are in green parts. During the period 1961-1998, it has been shown that phytomass of forest ecosystems in Russia increased from 29.59 to 34.30 Pg (=10^15g) C, i.e. annual average accumulation of carbon in phytomass is estimated at 127 Tg C yr^-1. NPP, calculated as smoothed average for a 5 year period, increased from 1488 Tg C yr^-1 in 1961 to 1735 Tg C yr^-1in 1998.