Spatial Distribution and Influencing Factors of Soil Organic Carbon in Tea Plantations in Guizhou Province
With the continuous expansion of tea plantation area,understanding the spatial distribution of soil organic carbon and its influencing factors is of great significance in guiding the construction of carbon sink tea plantations.In this study,we investigated the dominant factors affecting the spatial variability of soil organic carbon content in different soil layers of tea plantations.Soil samples from regional tea plantations and the surrounding woodlands and scrub grasslands in Guizhou Province were collected.GIS cluster analysis and the geographical detector model analysis were adopted in the study.The results showed that the soil organic carbon content of regional tea plantations ranged from 5.61 to 80.92 g·kg-1.The spatial distribution was moderately variable(coefficient of variation 0.47).The average content of soil organic carbon was 49.34,29.80,and 19.65 g·kg-1 in the three regions of woodland,tea plantation,and scrub grassland,respectively.The soil organic carbon content of tea plantations decreased with the increase of soil depth.Quantitative assessment revealed that elevation was the dominant factor influencing the spatial heterogeneity of soil organic carbon in tea plantations.The changes in elevation significantly affected regional temperature and rainfall.The spatial distribution of soil organic carbon in the surface layer was mainly influenced by temperature,while rainfall was the main influencing factor for the middle and lower soil layers.It was concluded that the carbon sequestration capacity and the carbon sink efficiency could be effectively increased by regulating the soil hydrothermal conditions in tea plantations.