AMOUNT AND QUALITY OF COARSE WOODY DEBRIS IN NATURAL AND MANAGED CONIFEROUS FORESTS NEAR THE TIMBERLINE IN FINNISH LAPLAND

Amount and structural characteristics of coarse woody debris (CWD) wer e studied in 44 stands of old-growth and managed coniferous forests in Finnish Lapland. The average volume of CWD in old-growth forests vari ed from 19 m(3) ha(-1) in pine forests to 60 m(3) ha(-1) in herb-rich spruce-dominated forests. The volumes of living and dead timber were h ighly correlated, the most productive sites having the highest volumes . In old-growth forests about 60-70% of the CWD was logs, 30-40% stand ing dead trees and snags, and 3.5-7% stumps and branches. The amount o f CWD decreased considerably in clear-cutting, but increased or remain ed the same in seed-tree and selective cuttings In the short term. How ever, the accumulation rate of new dead material was greatly reduced a fter cutting. In 40-year-old seed-tree cutting areas the new supply of CWD, created by recent disturbance and mortality, was less than 1% of the respective amount in old-growth forest. All cutting methods reduc ed standing dead trees and snags considerably.