Cao Zheng, Su Bao-Ling, Zhang Yan-Song, Sun Zhi-Hu, Zhou Li, Yu Da-Pao, Wang Qing-Wei
College of Life Science and Bioengineering, Shenyang University, Shenyang 110044, China.
CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Ying Yong Sheng Tai Xue Bao. 2025 Jul;36(7):1991-1999. doi: 10.13287/j.1001-9332.202507.003.
Thinning is a crucial silvicultural practice in forest management, the rational intensity of which plays an important role in increasing carbon sequestration capacity of forest ecosystems. However, it is not clear how different thinning intensities affect forest ecosystem carbon stocks and their fractions. We investigated plantations in the mountainous regions of eastern Liaoning Province, analyzed changes in carbon stocks and fractions with different thinning intensities (0, 10%-30%, 30%-50% and 50%-70%), and explored key factors influencing stand productivity and soil organic carbon dynamics. The results showed that tree biomass carbon stocks gradually decreased with increasing thinning intensity (from 110.89 Mg C·hm to 65.77 Mg C·hm) and that herbaceous biomass carbon stocks were significantly lower at different thinning intensities than in control stand, indicating that higher thinning intensities resulted in substantial carbon loss. Compared to the control stand, different thinning intensities increased the reserved individual tree biomass C increment, but only light thinning (25%) improved the reserved stand biomass C increment, suggesting that light thinning was the optimal intensity for plantations. Diffuse solar radiation was the main factor affecting reserved stand biomass increment. In 0-20 cm soil layer, particulate organic carbon (POC) stocks showed significant difference between different thinning intensities. POC stocks were positively correlated with litter biomass and soil C:N. In 20-40 cm soil layer, soil organic carbon (SOC) and POC stocks showed significant difference between different thinning intensities. SOC and POC stocks were negatively related to soil C:N and litter biomass, respectively. These results suggested that there are different mechanisms of SOC formation and stabilization in different soil layers.
间伐是森林经营中一项至关重要的营林措施，其合理强度对提高森林生态系统的碳固存能力起着重要作用。然而，不同间伐强度如何影响森林生态系统碳储量及其组分尚不清楚。我们对辽东山区的人工林进行了调查，分析了不同间伐强度（0、10%-30%、30%-50%和50%-70%）下碳储量及其组分的变化，并探讨了影响林分生产力和土壤有机碳动态的关键因素。结果表明，树木生物量碳储量随间伐强度增加而逐渐降低（从110.89 Mg C·hm降至65.77 Mg C·hm），不同间伐强度下草本生物量碳储量显著低于对照林分，表明较高的间伐强度导致大量碳损失。与对照林分相比，不同间伐强度增加了保留单株树木生物量碳增量，但只有轻度间伐（25%）提高了保留林分生物量碳增量，这表明轻度间伐是人工林的最佳强度。散射太阳辐射是影响保留林分生物量增量的主要因素。在0-20 cm土层中，不同间伐强度下颗粒有机碳（POC）储量存在显著差异。POC储量与凋落物生物量和土壤C:N呈正相关。在20-40 cm土层中，不同间伐强度下土壤有机碳（SOC）和POC储量存在显著差异。SOC和POC储量分别与土壤C:N和凋落物生物量呈负相关。这些结果表明，不同土层中SOC形成和稳定的机制不同。
