细柄阿丁枫天然林与杉木人工林土壤水稳性团聚体有机碳比较

A Comparison of Soil Organic Carbon of Water-Stable Aggregates between Altingia gracilipes Natural Forest and Cunninghamia lanceolata Plantation

研究福建省建瓯市万木林自然保护区内，细柄阿丁枫（Altingia gracilipes）天然林及杉木（Cunninghamia lanceolata）人工林不同土层土壤团聚体有机碳质量比与有机碳贮量的关系，探讨土地利用变化对土壤水稳性团聚体有机碳的影响．结果表明，细柄阿丁枫天然林和杉木人工林都是以大团聚体（〉0．25mm）为主，占了干土质量的85％以上．天然林转换为人工林后。土壤团聚体的数量变化差异不明显，但各个粒径团聚体有机碳质量比明显下降，下降幅度为22．62％～51．78％，表层土壤有机碳损失更为严重．2种林分的大于2．0mm的团聚体有机碳贮量最高，0．25～O．5mm的团聚体有机碳贮量最低，在大团聚体中呈现出随粒径增加，有机碳贮量增加的趋势．天然林转换为人工林后，土壤有机碳贮量明显下降，下降是由各粒径团聚体碳质量比减小引起的．

In order to assess the impacts of land use change on soil organic carbon （SOC）, the contents of SOC of water -stable aggregates of surface soil samples（0-10 cm, 10-20 cm）at a natural forest of Altingia gracilipes and a plantation of Chinese fir （Cunninghamia lanceolata ） were investigated in Wanmulin Nature Reserve of Jianou city, Fujian Province, China. Results showed that the proportion of macroaggregates （〉0. 25 ram） was account for 85%of the dry soil weight.There was no significant differences between the aggregate proportions of the two forest, but the contents of SOC in different size groups decreased significantly as natural forest conversion to plantation, and the loss of C content in aggregates was account for 22. 62% to 51.78%. The storages of SOC in different sized aggregates in two forests increased with increasing macroaggregate size. The total content of SOC was affected by the carbon of different sizes of aggregates. It is concluded that the conversion of natural forest into plantation leads to a loss of the content of SOC and soil aggregates and a decrease of the aggregates stability.