论文部分内容阅读
根据鼎湖山森林植被带(SL)、灌丛—草甸过渡带土壤剖面(GC)有机质含量,有机质Δ14C、δ13C值,土壤粘粒含量及孢粉分析结果,研究华南亚热带山地土壤有机质深度分布特征的成因机制。结果表明土壤有机质的深度分布特征与土壤剖面的发育过程密切相关,随深度增大,有机质的来源数量不断减少,而成土时间增加,分解作用导致的有机质含量降低幅度增大,有机质含量不断减少。土壤有机质14C表观年龄随深度增加,土壤有机质δ13C值与有机质含量的深度变化具有明显对应关系,这些都是土壤剖面发育过程中有机质不同更新周期组分呈规律性分解的结果。粘粒的深度分布反映土壤剖面淋滤淀积的特点,表明土壤剖面经受了长期成土风化。土壤剖面的上述特征均为剖面发育过程中不断沉积、不断成土的结果,表明土壤剖面成土演化对于有机质深度分布具有显著制约。
According to the soil organic matter content, the Δ14C, δ13C value of soil organic matter, the clay content and the pollen analysis results in the forest vegetation belt (SL) of Dinghushan Mountain, the soil organic matter content in the shrub-meadow transitional zone was studied. The mechanism of formation. The results showed that the depth distribution of soil organic matter was closely related to the development of soil profile. With the increase of depth, the source of organic matter decreased continuously, while the time of soil formation increased, the decrease of organic matter content caused by decomposition increased and the content of organic matter decreased . The apparent age of 14C of soil organic matter increased with depth, and there was a clear correspondence between the δ13C value of soil organic matter and the depth variation of organic matter content. These were the results of regular decomposition of components in different renewal periods of organic matter during soil profile development. The depth distribution of clay particles reflects the characteristics of leaching and deposition of soil profiles, indicating that the soil profile has undergone long-term soil-forming weathering. The above characteristics of the soil profile are the result of continuous sedimentation and continuous soil formation during the development of the profile, indicating that the evolution of soil profile in the soil profile has significant constraints on the depth distribution of organic matter.