Nitrogen addition stimulate random migration of plant community in a semiarid steppe

• Main Authors: Ping Wang, Minjie Xu, Wei Yang, Keyu Bai, Wei Liu, Zijia Zhang, Baoming Ji, Yi Fan, Ximei Zhang
• Format: Article
• Language: English
• Published: Elsevier 2021-04-01
• Series: Global Ecology and Conservation
• Subjects: N addition; Semiarid steppe; Migration; Dispersal
• Online Access: http://www.sciencedirect.com/science/article/pii/S2351989421000585

Increasing atmospheric nitrogen (N) deposition causes profound changes in the plant community, significantly threatening the terrestrial ecosystem function and stability worldwide. Random migration is a primary determinant of plant community assembly in the neutral model. However, whether its role is affected by N deposition is obscure. Therefore, the effects of eight N application rates (0, 1, 2, 3, 5, 10, 15, and 20 g N m−2 yr−1) on the estimated migration rate of plant community were examined in a long-term field study in a semiarid steppe. Our results indicated that N addition significantly impacted the estimated migration rate (F = 4.89, P < 0.001) and positively correlated with the N application rate (r2 = 0.32, P < 0.001). By constructing a structural equation model, we observed that the effect of N addition was mainly mediated through soil pH, moisture, and fungi: bacteria ratio. Mantel test revealed that the estimated migration rate was correlated with the plant community composition in moderate-N (10, 15, and 20 g N m−2 yr−1) treatment, but not in control (0 g N m−2 yr−1) and low-N treatment (1, 2, 3 and 5 g N m−2 yr−1) groups. Overall, our findings highlight the key role of N addition on plant community migration.