乌岩岭不同林分土壤有机碳含量及分布特征

Distribution of soil organic carbon among different forest types in Wuyanling Nature Reserve

【目的】浙江乌岩岭森林生态系统濒临太平洋,具有独特的海洋性气候,在中国亚热带地区具有重要地位,探究该区域不同林分土壤有机碳含量及其分布特征,可为提高土壤碳库管理水平,推动森林生态系统的可持续经营与发展提供参考。【方法】用岛津TOC-LCPH总有机碳分析仪测定了7种林分(松林、杉木林、柳杉林、阔叶林、混交林、竹林、茶园)土壤有机碳(SOC)及水溶性有机碳(WSOC)含量,并分析了其与土壤因子的关系。【结果】7种林分的SOC和WSOC含量都呈现出了随土层深度增加而减少的规律,具有明显的垂直分布特征。各土层SOC含量均以杉木林最高,≥10~25 cm与≥25~40 cm两土层WSOC含量亦是在杉木林中最高。WSOC与SOC含量之比为0.59%~1.51%,以杉木林≥25~40 cm土层的最高,以松林≥25~40 cm土层的最低。SOC含量与土壤密度、p H分别存在极显著(P<0.01)与显著线性负相关(P<0.05),WSOC含量与土壤密度、p H均存在极显著线性负相关(P<0.01)。【结论】乌岩岭土壤密度与p H均为影响林分SOC和WSOC含量的重要因素。

【Objective】Forest ecosystems at the Wuyanling Nature Reserve in Zhejiang Province close to the Pacific Ocean have a unique marine climate and play an important role in the subtropical region of China. Exploring the soil organic carbon content and its distribution characteristics among different forest types can provide information for improving the management of soil carbon pools and promoting sustainable management and development of forest ecosystems.【Method】The content of the soil organic carbon（ SOC） and soil water-soluble organic carbon（ WSOC） of seven forest types（ pine forest,Chinese fir forest,Cryptomeria fortunei forest,broad-leaved forest,mixed forest bamboo forest,and tea plantation） were determined by Shimadzu TOC-LCPHtotal organic carbon analyzer,and their correlations with soil factors were analyzed. 【Result】The SOC content and WSOC contents of all seven forest types decreased with increasing soil depth,showing obvious vertical distribution patterns. The SOC contents in all soil layers were the highest in the Chinese fir forest,and the WSOC contents in the soil layers ≥10-25 cm and ≥25-40 cm were also the highest in the Chinese fir forest. The percentage of WSOC to SOC varied from 0. 59% to 1. 51%,among which the highest was found in the layer≥25-40 cm in the Chinese fir forest and the lowest was found in the layer ≥25-40 cm of the pine forest. There was an extremely significant negative linear correlation between SOC and bulk density（ P〈0.01）,and a significant negative linear correlation of SOC with p H（ P〈0. 05）. The content of WSOC showed an extremely significant negative linear correlation with both soil bulk density and p H（ P〈0.01）. 【Conclusion】Soil bulk density and p H are both important factors affecting SOC and WSOC contents in the Wuyanling Nature Reserve.