海南岛东北部5种森林土壤有机碳分布特征

为揭示海南岛东北部森林土壤有机碳分布特征,本文对该区湿加松林（Pinus elliottii×P. caribaea）、木麻黄林（Casuarina equisetifolia）、椰树林（Cocos nucifera）、次生林和混交林等5种典型森林土壤有机碳含量和储量进行了比较研究。结果表明,5种森林0~100 cm土壤有机碳平均含量差异显著（P<0.05）,其中次生林最高,为3.78 g/kg,木麻黄林最低,仅有0.90 g/kg;5种森林0~100 cm土壤有机碳储量分别为次生林46.06 t/hm ²、混交林40.52 t/hm ²、湿加松林39.08 t/hm ²、椰树林31.26 t/hm ²和木麻黄林15.22 t/hm ²。浅海沉积土上的次生林、滨海沙土上的混交林均具有相对较高的土壤有机碳储量,分别显著地高于同一母质上的椰树林和木麻黄林（P<0.05）。综上,该区不同类型森林的建立深刻地影响了土壤有机碳库储量,次生林和混交林的建立可能有助于该区增加土壤固碳。

Soil Organic Carbon Distribution in Five Forest Types in the Northeast of Hainan Island

To reveal the soil organic carbon (SOC) distribution characteristics in different forest types in Northeastern Hainan, the data of SOC content and storage under five forest types (Pinus elliottii×P. caribaea, Casuarina equisetifolia, Cocos nucifera, Secondary forest and Mingled forest) in this region were analyzed. The results showed that in the 0-100 cm soil profile, the average SOC content of the five forests was significantly different (P<0.05). The highest was found in the secondary forest soil (3.78 g/kg), while in Casuarina equisetifolia the values were the minimum (0.90 g/kg); SOC storage values were 46.06 t/hm ² in the secondary forest, 40.52 t/hm ² in the mingled forest, 39.08 t/hm ²in Pinus elliottii×P. caribaea, 31.26 t/hm ² in Cocosnucifera and 15.22 t/hm ² in Casuarina equisetifolia. The secondary forests on shallow marine deposits and mingled forests on coastal sandy soil had relatively high SOC storage, which were significantly higher than Cocos nucifera and Casuarina equisetifolia on the same parent material respectively (P<0.05). In summary, the planting of different types of forests within this region would have a profound prospect on SOC storage, and the establishment of secondary forests and mingled forests may help the increment of SOC sequestration.