海南岛北部地区红树林湿地土壤有机碳分布规律及影响因素

红树林是单位生产力最高的生态系统之一,能够持续地固定有机碳,对全球碳平衡及生物地球化学循环有深远影响。在海南岛北部东寨港、八门湾、新盈港地区等典型红树林湿地的林内、林缘和光滩开展垂直采样,共采集15个样点,在室内对样品的有机碳含量、物理化学性质进行分析,探讨红树林湿地土壤有机碳的分布规律以及影响碳储量的主要因素。结果显示:红树林湿地0～40cm土壤有机碳含量为0.88～134.00g/kg,平均为25.18(±10.34)g/kg。在空间分布上,表现为八门湾红树林(36.61g/kg±4.46g/kg)东寨港红树林(25.57g/kg±3.14g/kg)新盈红树林(13.36g/kg±1.71g/kg);水平分布规律为林内(41.69g/kg±0.71g/kg)林缘(21.24g/kg±0.43g/kg)光滩(13.88g/kg±0.32g/kg);垂直分布最大值出现在10～20cm土层,为32.11(±3.45)g/kg。进一步相关分析显示,土壤有机碳含量与粘粒和粉粒呈极显著正相关关系,与砂粒和pH值呈极显著负相关关系。

Distribution of soil organic carbon in mangrove wetlands in the north areas of Hainan Island and its controls

Mangrove is one of the most productive ecosystems, which can sequestrate soil organic carbon continuously and has a profound influence on the global carbon balance and biogeochemical cycle. In the north areas of Hainan Island, typical mangrove wetlands (Dongzhai Harbor, Bamen Bay and Xinying Harbor) were selected for soil sampling. A total of 105 soil samples were collected from 15 sites. The samples were analyzed for soil organic carbon (SOC) content, particle size and pH, exploration was done of SOC distribution and its controls. Results showed that the SOC content in 0-40 cm mangrove wetlands was between 0.88 g/kg and 134.00 g/kg, with an average value of 25.18 (±10.34) g/kg. The SOC content was in the order of inside of forest (41.69±0.71 g/kg) > forest edge (21.24±0.43 g/kg) > light beach (13.88±0.32 g/kg). It varied with soil depth, the peak of SOC content appeared in 10-20 cm (32.11±3.45g/kg). As to spatial distribution, a decreasing order of Bamen Bay Wenchang (36.61±4.46 g/kg) > Dongzhai Harbor Haikou (25.57±3.14 g/kg) > Xinying Bay Lingao (13.36±1.71 g/kg) was observed. The correlation analysis showed that SOC content was significantly correlated with clay and silt, and was negatively correlated with sand. and pH