Wu Jiabing

Ecological functions of coarse woody debris in forest ecosystem

Coarse woody debris is an important structure and function unit in forest ecosystem. This review analyzed the ecological functions of coarse woody debris in forest ecosystem and introduced several hotspots and existing problems in coarse woody debris research field. It is suggested that quantitative research should be intensified in the ecological demands of coarse woody debris for providing a technical guidelines in management of productivity, biodiversity and other ecological processes.

Dynamics of profiles and storage of carbon dioxide in broadleaved/Korean forest in Changbai Mountain

CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected data, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 μmol·mol−1, but had a significant change in July, with a difference of 60 μmol·mol−1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 μmol·mol−1. The calculated total storage (ΔC/Δt) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.