Effect of Stand Age on Soil Carbon Degradation Enzyme Activity in Pinus massoniana Plantation

To investigate the effect of age on soil carbon degradation enzyme activity in Pinus massoniana plantation, the chronosequence study involving different stands (5, 9, 19, 29, 35 years old) was conducted, in which enzymatic activities of β-glucosidase, cellobiohydrolase, polyphenol oxidase and peroxidase were quantified, along with correlation analyses to evaluate their relationship with soil physicochemical properties. The activities of both soil hydrolase (e.g., β-glucosidase and cellobiohydrolase) and oxidase (e.g., polyphenol oxidase and peroxidase) exhibited an upward tendency with the stand age increasing, indicating the synergistic enhancement of carbon metabolic functional groups during this stand development. Further analysis revealed activities of soil hydrolase and oxidase were positively related to soil potassium content. In conclusion, this study provides a theoretical framework for analyzing the mechanism of soil carbon-nutrient interaction, emphasizes the importance of soil nutrient management in the sustainable management of P. massoniana plantation.