变薄-一种广泛使用的森林管理实践-可以显着影响亚热带森林中的土壤氮(N)循环过程。然而,不同稀释强度对硝化作用的影响,反硝化,它们与土壤特性和微生物群落的关系仍然知之甚少。这里,我们在中国亚热带森林中进行了一项研究,并应用了三种间伐处理,即,无变薄(0%),中间变薄(10-15%),和严重变薄(20-25%),并研究了稀化强度对潜在硝化速率(PNR)的影响,潜在反硝化速率(PDR),和微生物群落。此外,我们探索了土壤理化性质之间的关系,微生物群落结构,不同间伐强度下的氮转化率。我们的结果表明,与对照相比,中等间伐和重度间伐将PNR显着增加了87%和61%,并将PDR降低了31%和50%,分别。尽管细菌群落结构明显受到变薄的影响,真菌群落结构保持稳定。重要的是,微生物群落组成和多样性的变化对氮转化过程的影响最小,而土壤理化性质,如pH值,有机碳含量,和氮的形式,被确定为主要驱动因素。这些发现强调了管理土壤理化性质对调节森林土壤氮素转化的关键作用。有效的森林经营应注重精确调整间伐强度,增强土壤理化条件,从而促进更有效的氮循环,改善亚热带地区的森林生态系统健康。
Thinning-a widely used forest management practice-can significantly influence soil nitrogen (N) cycling processes in subtropical forests. However, the effects of different thinning intensities on nitrification, denitrification, and their relationships with soil properties and microbial communities remain poorly understood. Here, we conducted a study in a subtropical forest in China and applied three thinning treatments, i.e., no thinning (0 %), intermediate thinning (10-15 %), and heavy thinning (20-25 %), and investigated the effects of thinning intensity on the potential nitrification rate (PNR), potential denitrification rate (PDR), and microbial communities. Moreover, we explored the relationships among soil physicochemical properties, microbial community structure, and nitrogen transformation rates under different thinning intensities. Our results showed that intermediate and heavy thinning significantly increased the PNR by 87 % and 61 % and decreased the PDR by 31 % and 50 % compared to that of the control, respectively. Although the bacterial community structure was markedly influenced by thinning, the fungal community structure remained stable. Importantly, changes in microbial community composition and diversity had minimal impacts on the nitrogen transformation processes, whereas soil physicochemical properties, such as pH, organic carbon content, and nitrogen forms, were identified as the primary drivers. These findings highlight the critical role of managing soil physicochemical properties to regulate nitrogen transformations in forest soils. Effective forest management should focus on precisely adjusting the thinning intensity to enhance the soil physicochemical conditions, thereby promoting more efficient nitrogen cycling and improving forest ecosystem health in subtropical regions.