Abstract
It has been noticed that dissolved organic carbon (DOC) in throughfall and stemflow is possibly significant input for the carbon cycle in forest ecosystems. The purpose of this study is to estimate annual DOC flux of throughfall and stemflow by combining data from the field measurement with the calculation from multiple-regression analysis using meteorological factors, then to compare results to previous reports. Weighted average concentrations of DOC in throughfall and stemflow were 8.0 and 19.8 mgC 1-1 for Quercus serrata, 15.1 and 37.4 mgC 1-1 for Pinus densiflora, respectively. DOC concentrations were regressed by the global solar radiation for throughfall and stemflow of Quercus serrata and stemflow of Pinus densiflora, while it was predicted by the temperature and the duration of fine hours for throughfall of Pinus densiflora. Those results supposed DOC concentration of throughfall and stemflow were affected by the factor relating to physiology of trees. The annual DOC flux of throughfall and stemflow were estimated at 142 and 6.7 kgC ha-1 yr for Quercus serrata, 322 and 12.4 kgC ha yr-1 for Pinus densiflora. Comparing our results with previous reports, DOC flux for hardwoods correlate with precipitation and that of Pinus densiflora was larger than other coniferous species.
