Authors: Kenji Ono Syuntaro Hiradate Sayaka Morita Kenji Ohse Keizo Hirai
Publish Date: 2010/05/06
Volume: 338, Issue: 1-2, Pages: 171-181
Abstract
We quantitatively clarified the early humification processes on Japanese cedar and Hinoki cypress forest floors by using a litterbag experiment and the solidstate 13C CPMAS NMR technique There was no significant effect on litter mass loss during early humification between both coniferous litters regardless of the shape of their needles Carbon composition in both litters showed similar trends during early humification A/OA as a humification index was low around 06 in both litters throughout the experiment period although 60 of litter mass was lost Coniferous litter incubated for 3 years might not be wellhumified and would be susceptible to physical fragmentation Carbon mass loss rates in conifers were in the following order Oalkyl aliphatic aromatic carbonyl carbons differing with hardwoods Conifers had concomitantly higher and lower mass loss rates of aliphatic and aromatic carbons than hardwoods Soil organic carbon SOC accumulated in topsoil for conifers had relatively high and low contents of aliphatic and aromatic carbons than that for hardwood These compositional differences of SOC among forests could be caused by the high and low supply rates of aliphatic and aromatic carbons from litter to topsoil Consequently initial litter nature and humification processes can affect the compositional qualities of SOC accumulated in soilWe are grateful to Drs Shinji Kaneko Masamichi Takahashi Yojiro Matsuura Makoto Araki and Eriko Ito for their valuable advice and comments and we thank Ms Yumiko Okazaki and Teru Notsukidaira for their help with sample preparation and laboratory analysis We wish to express our appreciation to the staff of the Department of Forest Site Environment Tohoku Research Center and the Arboretum and Nursery Office in the Forestry and Forest Products Research Institute Their advice and assistance were extremely helpful during our fieldwork and experiments This study was supported in part by a program of the Japanese Ministry of the Environment entitled “Evaluation Adaptation and Mitigation of Global Warming in Agriculture Forestry and Fisheries Research and Development A1120” and the program of the Japanese Ministry of Education Culture Sports Science and Technology for Young Scientists entitled “Study on the production process of humic substances in forest soil by noting recalcitrant lignin compounds No 20780122”
Keywords: