海南热带橡胶园土壤易氧化有机碳空间变异特征研究

Spatial variability of soil labile organic carbon in the tropical rubber plantations of Hainan province,China

为了解热带橡胶园土壤活性有机碳状况,采集了海南全岛13个不同胶园土壤,用高锰酸钾氧化-比色法测定了土壤易氧化有机碳质量分数,分析了其影响因素。结果表明,海南橡胶园土壤易氧化有机碳质量分数平均为2.70 g.kg-1（以C计）,变化在0.92~6.82 g.kg-1之间,变幅达到641%。易氧化有机碳质量分数与土壤有机质、全磷和全氮显著正相关,同时受成土母质的强烈影响,玄武岩发育的土壤最有利于易氧化有机碳累积,砂页岩和花岗岩次之,而变质岩和浅海沉积物形成的土壤易氧化有机碳质量分数较低。土壤易氧化有机碳质量分数也受气候强烈影响,随湿度降低而下降。

To evaluate the spatial variation of soil labile organic carbon（LOC） in the tropical rubber plantations,soil samples were collected around Hainan Island and LOC was determined using the potassium permanganate oxidation method.The content of soil LOC averaged 2.70 g·kg-1 soil,with a range varying from 0.92 to 6.82 g·kg-1 soil.The variation coefficient of the mean amounted to 641%,indicating that there was a large variability of soil LOC in rubber plantations around Hainan.Soil LOC was significantly correlated with soil organic matter,total phosphorus and total nitrogen,but not with total potassium contents in soil.The parent materials significantly affected LOC contents in soils.Soil derived from basalt had the highest LOC,followed by sandstone,shale and granite,whereas the lowest was observed for metamorphic rock and neritic sediments.Soil LOC content was also impacted by climate conditions,and roughly decreased with the reduction of humidity.