Different responses of soil fungal and bacterial communities to nitrogen addition in a forest grassland ecotone

作者：Daiyan Li, Meng Meng, Baihui Ren, Xinwei Ma, Long Bai, Jiahuan Li, Guohua Bai, Fengjun Yao, Chunming Tan · 发表于：Frontiers in Microbiology · 年份：2023 · DOI：10.3389/fmicb.2023.1211768 · 被引用次数：10 · 研究领域：Biocrusts and Microbial Ecology、Soil Carbon and Nitrogen Dynamics、Microbial Community Ecology and Physiology

Introduction Continuous nitrogen deposition increases the nitrogen content of terrestrial ecosystem and affects the geochemical cycle of soil nitrogen. Forest-grassland ecotone is the interface area of forest and grassland and is sensitive to global climate change. However, the structure composition and diversity of soil microbial communities and their relationship with soil environmental factors at increasing nitrogen deposition have not been sufficiently studied in forest-grassland ecotone. Methods In this study, experiments were carried out with four nitrogen addition treatments (0 kgN·hm −2 ·a −1 , 10 kgN·hm −2 ·a −1 , 20 kgN·hm −2 ·a −1 and 40 kgN·hm −2 ·a −1 ) to simulate nitrogen deposition in a forest-grassland ecotone in northwest Liaoning Province, China. High-throughput sequencing and qPCR technologies were used to analyze the composition, structure, and diversity characteristics of the soil microbial communities under different levels of nitrogen addition. Results and discussion The results showed that soil pH decreased significantly at increasing nitrogen concentrations, and the total nitrogen and ammonium nitrogen contents first increased and then decreased, which were significantly higher in the N10 treatment than in other treatments (N:0.32 ~ 0.48 g/kg; NH 4 + -N: 11.54 ~ 13 mg/kg). With the increase in nitrogen concentration, the net nitrogen mineralization, nitrification, and ammoniation rates decreased. The addition of nitrogen had no significant effect on ...