Spatial variation of soil organic carbon under major rubber planting regions in China

Abstract Understanding the dynamic relationships between soil organic carbon (SOC) and stand age are essential to quantify and predict the terrestrial carbon sequestration potential. However, the spatial patterns in the response of rubber plantation SOC to stand age and their driving factors remain unclear. Based on SOC and its components measurement at different soil depths (0–40 cm) in rubber plantations under five different age classes (0–5, 5–10, 10–20, 20–30, and >30 years) in three major rubber cultivation regions in China, distribution pattern and controlling factors of SOC were investigated. We found that SOC and its components showed significant spatial variability vertically with soil depth and laterally across sampling sites. SOC contents in three major rubber cultivation regions range from 4.48 to 20.13 g kg −1 at a depth of 0–40 cm. Among the sampling sites, Jinghong had the highest SOC content at a depth of 0–10 cm (20.13 g kg −1 ). On a large‐scale, the relationship between SOC and stand age in rubber plantations did not show a consistent pattern among different sampling sites. Additionally, annual rainfall, soil moisture content, and soil pH had a stronger impact on SOC in rubber plantations compared to stand age. The results indicated that the spatial variability of SOC in rubber plantations with stand age could be influenced by specific soil properties and climate‐related variables at each sampling site. This study emphasized the significance of conducting multi‐site, multi‐scale studies to enhance our understanding of SOC dynamics and its influencing factors, and help to more accurately predict the dynamic changes of soil carbon storage in rubber plantations.