Decomposition of Coarse Woody Debris in Forest Ecosystem: a Review

Coarse woody debris(CWD) is an important and sensitive carbon as well as the nutrient pool in forest ecosystem. It has a vital role in the research of carbon cycle and balance. Grasping the methodological system and influencing factors of CWD decomposition is important for the energy flow and material cycle of forest ecosystem, judging its position and role in the global carbon cycle and carbon balance, improving forest management strategies, and maintaining the integrity and stability of forest ecosystem. It is summarized the progress of CWD decomposition respiration in the review: decomposition process, decomposition rate quantification methods, decomposition process model and main factors. There are 3 methods for studying decomposition rates(long-term monitoring method, chronosequences, and decomposition vector) and the main factors driving decomposition, in addition to their characteristics (species controls, piece size, stand and downed position), are also influenced by environmental factors, such as mainly temperature and moisture, light intensity, canopy openness and atmospheric nitrogen deposition, stand habitat conditions, decomposers(type, home-field advantage). By analyzing the shortcomings of the current CWD decomposition studies, 3 perspectives are proposed: 1) to establish a long-term monitoring system and use high-precision time-resolved data to understand the dynamic changes of CWD decomposition at different scales; 2) to improve the decomposition model, conduct long-term monitoring studies on CWD decomposition, and explore the differences and similarities of decomposition patterns in different regions; 3) to consider the net ecosystem carbon flux characteristics caused by disturbance-induced decomposition changes and the influence of heterogeneous habitats on CWD decomposition.