Nitrogen deposition reduces biodiversity but strengthens plant–microbe interactions
Zonghao Hu,
Yi Fan,
Junjie Yang,
Shuang Pang,
Rong Mao,
Yang Zhang,
Xingguo Han,
Ximei Zhang
Affiliations
Zonghao Hu
Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; State Key Laboratory of Efficient Utilization of Agricultural Water Resources, CAU/CAAS, China
Yi Fan
Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; State Key Laboratory of Efficient Utilization of Agricultural Water Resources, CAU/CAAS, China
Junjie Yang
Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
Shuang Pang
Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; State Key Laboratory of Efficient Utilization of Agricultural Water Resources, CAU/CAAS, China
Rong Mao
College of Forestry, Jiangxi Agricultural University, No. 1101 Zhimin Road, Nanchang 330045, China
Yang Zhang
College of Forestry, Jiangxi Agricultural University, No. 1101 Zhimin Road, Nanchang 330045, China
Xingguo Han
School of Life Sciences, Institute of Life, Science and Green Development, Hebei University, Baoding, Hebei 071002, China
Ximei Zhang
Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; State Key Laboratory of Efficient Utilization of Agricultural Water Resources, CAU/CAAS, China; Corresponding author.
Nitrogen deposition can reduce plant and soil microbial diversity, and thus, it was traditionally thought to decouple plant–microbe interactions. However, few studies quantified these interactions directly and systematically. Here, we conducted a long-term nitrogen deposition experiment with nine rates (0–50 g nitrogen m−2 yr−1) in the Eurasian steppe. Although nitrogen addition reduced biodiversity, it strengthened the relationships between plant and microbial community indices (biomass, richness, and composition) in a structural equation model, increased the Pearson’s correlation coefficient (r) between plant biomass and microbial biomass, and also increased the density of the plant–microbe interaction subnetwork. These results challenge the traditional decoupling viewpoint and indicate that plant–microbe interactions strengthen to adapt to increasing nitrogen deposition pressure.
