热带滨海台地典型森林类型凋落物及土壤有机碳特征

以海南岛滨海台地5种典型森林植被为研究对象,利用标准地调查法对不同森林类型土壤有机碳含量、有机碳密度及单位面积有机碳储量的垂直分布特征进行比较分析,同时对不同森林类型凋落物及土壤表层细根的碳含量、碳密度和单位面积碳储量进行对比分析。结果表明:5种森林土壤有机碳含量介于1.79~10.60 g/kg之间,且随着土层深度的增加而降低;表层土壤(0~10 cm)有机碳密度和单位面积碳储量分别介于0.79~1.47 kg/m2和7.9~14.67 t/hm2之间;桉树林(2.11 t/hm2)和木麻黄林(1.73 t/hm2)凋落物单位面积碳储量高于其他3种林分;5种类型森林土壤表层细根单位面积碳储量介于0.29~0.47 t/hm2之间,木麻黄林最高(0.47 t/hm2),大叶相思林最低(0.29 t/hm2)。

Characteristics of Soil Organic Carbon and Litter of Typical Forest Types in Tropical Coastal Zone

The carbon content, density and carbon stock per unit area of litter amount, soil fine roots and soil organic carbon(SOC)properties of typical forest types were contrastively analyzed by standard block investigation in tropical coastal zone, Hainan. Results showed SOC content of 5 stands changed between 1.79-10.60 g/kg and decreased with the increase of soil depth. SOC density and carbon storage per unit in soil surface(0~10 cm)changed between 0.79-1.47 kg/m2 and 7.9-14.67 t/hm2; Carbon storage per unit of litter in Eucalyptus robusta(2.11 t/hm2)and Casuarina equisetifolia forest(1.73 t/hm2)was higher than the other 3 types of forest. Carbon storage of fine-root of 5 stands changed between 0.29-0.47 t/hm2 in soil surface(0-40 cm), Casuarina equisetifolia forest had the highest value(0.47 t/hm2)well the value in stand of Acacia auriculiformis was the lowest. The litter carbon storage and SOC were influenced by vegetation type, environmental conditions andexternal disturbance etc. Secondary forest with complex structures and species composition had the highest SOC, the management strategy according to the structures and composition of secondary forest could play an important role in increasing the carbon stock intropical coastal zone