海南西部热带雨林次生林土壤易氧化有机碳分布特征及影响因素

Distribution Characteristics and Influencing Factors of Soil Readily Oxidized Organic Carbon of Secondary Rainforests in Western Hainan Province

【目的】研究土壤易氧化有机碳(ROC)的分布特征及其主要影响因素,为提高热带雨林“固碳”能力和缓解全球气候变暖方面提供科学依据。【方法】以海南省西部尖峰岭、霸王岭、鹦哥岭外围次生林的土壤作为研究对象,在分析其土壤总有机碳(SOC)特征的基础上,运用相关分析和线性回归分析探讨区域内土壤ROC的分布规律及与环境因素的相关性。【结果】尖峰岭、霸王岭、鹦哥岭次生林土壤ROC含量排序为尖峰岭<霸王岭<鹦哥岭,与SOC含量分布特征变化规律一致。在土壤垂直剖面上,土壤ROC含量随着土层的增加而逐渐减小;0~10 cm土层ROC含量与10~30、30~50 cm土层差异显著;土壤0~50 cm剖面ROC分配比例表现为:霸王岭>鹦哥岭>尖峰岭。尖峰岭和霸王岭ROC含量与粉粒+黏粒呈极显著负相关,而鹦哥岭ROC含量与粉粒+黏粒呈极显著正相关。尖峰岭、霸王岭、鹦哥岭3座山地pH值与ROC均为显著相关,ROC含量与pH值的相关性强弱大小依次为霸王岭>鹦哥岭>尖峰岭。【结论】次生林ROC含量不仅受SOC含量的影响,土壤理化性质(pH、土壤质地分布)、土壤总有机碳等多个环境要素也对区内土壤次生林ROC的分布起到一定的决定性作用。

【Objective】The distribution characteristics and influencing factors of soil readily oxidized organic carbon(ROC)were investigated in order to provide a scientific basis for improving the“carbon sequestration”capacity of tropical rainforests and alleviating global warming.【Method】The soil of the peripheral secondary forests of Jianfengling,Bawangling and Yinggeling in western Hainan Province was used as the research object.Based on the analysis of soil organic carbon(SOC)characteristics,correlation analysis and linear regression analysis were used to explore the corelation between the distribution laws of soil ROC and the environmental factors in the study regions.【Result】ROC content in soil of secondary forests ranked as:Jianfengling<Bawangling<Yinggeling,which was consistent with the law of the distribution characteristics of the SOC.On the vertical profiles of soil,the ROC content gradually decreased with the increase in soil depths.The ROC content in the 0-10 cm soil layer was significantly different from that in the 10-30 cm and 30-50 cm soil layers.The proportion of ROC in the 0-50 cm profile was showed as:Bawangling>Yinggeling>Jianfengling.There was an extremely significant and negative correlation between ROC with silt and clay soil on Jianfengling and Bawangling,and was an extremely significant and positive correlation between ROC with silt and clay soil on Yinggeling.Both the pH value and ROC content of these three mountains were extremely significantly correlated.The correlation between ROC content and pH value ranked as:Bawangling>Yinggeling>Jianfengling.【Conclusion】The ROC content of secondary forests is not only affected by the soil organic carbon content,but also by a number of environmental factors such as soil physiochemical properties(pH,soil texture distribution),soil total organic carbon and other environmental factors,which also play a certain role in determining the distribution of ROC in soil of secondary forests.