鹅凰嶂季雨林土壤有机碳特征及空间分布规律

Spatial distribution of soil organic in E’huangzhang monsoon forest

为了解土壤总有机碳和易氧化有机碳的空间分布格局及其剖面垂直分布规律,量化了广东鹅凰嶂季雨林不同空间位置的0~10、10~30、30~60和60~100 cm土层的总有机碳和易氧化有机碳的分布特征及其他理化因子。结果表明:鹅凰嶂季雨林土壤4个土层平均总有机碳含量为22.73 g·kg^(-1),易氧化有机碳含量为2.96 g·kg^(-1)。0~10与10~30 cm土层土壤的总有机碳和易氧化有机碳含量有显著差异。土壤总有机碳含量在土壤剖面表现的大小关系为:0~10 cm(30.60 g·kg^(-1))>10~30 cm(19.44 g·kg^(-1))>30~60 cm(16.31 g·kg^(-1))>60~100 cm(15.63 g·kg^(-1))。土壤易氧化有机碳含量的大小关系为:0~10 cm(3.16 g·kg^(-1))>10~30 cm(2.34 g·kg^(-1))>30~60 cm(0.81 g·kg^(-1))>60~100 cm(0.40 g·kg^(-1)),土壤易氧化有机碳占总有机碳的比例呈现随土层加深先上升后下降的趋势,30~100 cm土层土壤有机碳稳定性优于0~30 cm土层的土壤。坡向和坡度对土壤总有机碳和易氧化有机碳含量影响均不显著。土壤含水量、土壤全磷含量对土壤总有机碳和易氧化有机碳影响极显著(P<0.01),土壤全氮含量与土壤总有机碳呈极显著正相关(P<0.01),与易氧化有机碳呈显著正相关(P<0.05)。研究结果揭示了土壤有机碳与易氧化有机碳存在不一样的空间横向分布规律,可为该区域准确估算森林土壤碳储量和资源合理利用提供数据支撑。

In order to understand the spatial distribution pattern and vertical distribution of soil total organic carbon and easily oxidized organic carbon,this study quantified the distribution characteristics of total organic carbon,easily oxidized organic carbon and other physical and chemical factors in four soil layers including 0~10,10~30,30~60 and 60~100 cm in different spatial locations of E’huangzhang monsoon forest in Guangdong Province.The results showed that the average total organic carbon and easily oxidized organic carbon contents of four soil layers were 22.73 and 2.96 g·kg^(-1),respectively,in the E’huangzhang monsoon forest.The soil total organic carbon and easily oxidized organic carbon contents were significantly different in 0~10 and 10~30 cm soil layers.The total organic carbon contents in the soil profile showed that:0~10 cm(30.60 g·kg^(-1))>10~30 cm(19.44 g·kg^(-1))>30~60 cm(16.31 g·kg^(-1))>60~100 cm(15.63 g·kg^(-1)).And the easily oxidized organic carbon contents showed as:0~10 cm(3.16 g·kg^(-1))>10~30 cm(2.34 g·kg^(-1))>30~60 cm(0.81 g·kg^(-1))>60~100 cm(0.40 g·kg^(-1)).The ratios of easily oxidized organic carbon to total organic carbon presented first increased and then decreased from the top to deep layer.Compared with the soil of 0~30 cm,the total organic carbon of 30~100 cm was more stable.Slope direction and slope position did not significantly influence the soil total organic carbon and easily oxidized organic carbon contents.Soil water content and soil total phosphorus content had significant effects on total organic carbon and easily oxidized organic carbon(P<0.01).Soil total nitrogen content had a significant effect on soil total organic carbon(P<0.01).Soil total nitrogen content significantly positively correlated with soil easily oxidized organic carbon(P<0.05).This study reveals that total organic carbon and easily oxidized organic carbon have different spatial distribution rules,which can provide data support for accurately estimating the forest soil carbon storage and rational utilization of resources in the E’huangzhang monsoon forest.