Abstract: In this paper, tree mortality, coarse woody debris(CWD)storage, its decomposition rate and role in nutrient cyclings in two temperate forest ecosystems of Changbai Mountain Natural Reserve of China and Andrews Experimental Forests of USAwere studied. Resuits show that CWDis an important component in temperate natural forest ecosystems. Its functional importance varies with forest types and decreases from coniferous forest to mixed forest. Aprimary role of CWDin nutrient cyclings within forest may be to retain nutrients and stabilize ecosystem following major natural disturbances. Global estimation of carbon stored in detritus should include CWDin future, otherwise, it is possible to underestimate 2—16×10¹³kg of global carbon storage in forest detritus, or relative error in system is 2—10%.

Key words: Coarse woody debris, Tree mortality, Decomposition rate, Nutrient storage, Carbon storage, Forest detritus