FOREST PHYTOMASS AND CARBON IN EUROPEAN RUSSIA

Regression equations for fractions of forest phytomass have been devel oped for European Russia (including the Urals). These equations are ba sed on available data and findings given in publications (962 sample p lots have been examined). The analyses cover pine, spruce, oak, birch, beech, aspen, alder, and lime species. Together these eight species c onstitute some 95% of the tree cover of the forested areas in European Russia. The equations allow us to evaluate the ratio between the weig ht of phytomass fractions and growing stock by species, age classes, a nd site indices. Application of the phytomass results to the Forest St ate Account (FSA) data (1988) gives an estimate of a total (living) ph ytomass in the forest ecosystems of forested areas of European Russia (166 million hectares of forested area, 20.28 billion m(3) of growing stock) of 15.47 petagrams (Pg) of dry matter (which corresponds to a d ensity of 9.32 kg/m(2)). The total carbon pool is estimated to be 7.64 Pg of carbon (C) with an overage density of 4.60 kg C/m(2) in 1988. S ensitivity analyses of data and methods show that the results of the e quations probably underestimate the values for phytomass and carbon by about 5%. Total phytomass in the forest vegetation of forested areas based on the 1993 FSA inventory is estimated to be 16.94 Pg (with an a verage density of 10.36 kg/m(2)) and the total C content is estimated to be 8.37 teragrams (Tg) (with an average density of 5.03 kg/m(2)). C hanges in the total forest phytomass of the forested areas during the 1966-1993 period were estimated to be 4.73 Pg (or about 174 Tg of dry matter per year), and the carbon content increased by 2.34 Pg. Thus, b etween 1966 and 1993 European Russian forests were a net sink for carb on and stored and absorbed an average of about 87 Tg of C annually. (C ) 1997 Elsevier Science Ltd.