Successive Planting of Eucalyptus grandis Plantations Reduce Soil Organic Carbon and Its Labile Fractions

作者：Zhi Zhao, Jingxing Tan, Xiao Luo, Renping Wan, Zepeng Liang, Xingcheng Zou, Ang Si, Sheng Wang, Junxi Hu, Shixing Zhou, Congde Huang · 发表于：Forests · 年份：2025 · DOI：10.3390/f16111621 · 被引用次数：3 · 研究领域：Soil Carbon and Nitrogen Dynamics、Forest ecology and management、Soil Management and Crop Yield

Soil organic carbon (SOC) is a critical component of the soil carbon pool, significantly influencing soil fertility and forest ecosystem productivity. Eucalyptus grandis (Rose Gum), one of the most widely introduced and economically valuable fast-growing tree species worldwide, plays an indispensable role in pulpwood production, construction, and bioenergy, and is commonly established and managed in successive rotations in operational practice. Despite its importance, the effects of successive planting on SOC and its labile fractions in plantation soils remain poorly understood. In May 2017, a space-for-time substitution approach was employed to study the effects of successive planting of E. grandis plantations on SOC and its labile fractions, including dissolved organic carbon, light-fraction organic carbon, particulate organic carbon, microbial biomass carbon, and readily oxidizable carbon. The results indicated that the content of SOC and labile organic carbon (LOC) fractions declined concomitant with an increase in successive planting generations. Specifically, total SOC content significantly decreased from 12.63 g·kg−1 in the first-generation forest to 9.37 g·kg−1 in the third-generation forest. The contents of LOC fractions also showed a significant decrease from the first to the second generation, but the rate of this decline slowed in the third generation. The soil carbon pool management index (CPMI) decreased significantly from 100 in the control forest to 46.64 in t...