Soil urease activity is mediated more by <i>ureC</i> microbial diversity in wet regions than dry regions: Key roles of generalist‐abundant and ‐rare species

Abstract The activity of soil urease regulates the hydrolysis of urea in the soil, and is affected by the climate, the properties of the soil and microorganisms. The relationships between soil urease activity and ureC microbial diversity are unclear in orchard ecosystems in wet and dry areas. Accordingly, 242 soil samples were collected from 10 main apple producing provinces in China. At the same time, high‐throughput sequencing technology was employed to assess the relative contributions of ureC microbial diversity, community composition and network complexity to soil urease activity under varying climatic conditions. The soil pH was the main factor that affected urease activity and ureC microbial diversity in both areas. However, urease activity increased more as ureC microbial diversity increased in wet areas (pathway value = 0.241), while it increased as soil organic matter increased in dry areas (pathway value = 0.238). The diversity of the ureC microbial community was positively correlated with the diversity of generalist‐abundant and generalist‐rare species ( R = 0.63; R = 0.71). Generalist‐abundant species positively affected the urease activity in orchards in both dry and wet areas. In wet areas, urease activity was also positively affected by the diversity of the generalist‐rare subcommunities. The ureC microbial composition differed between the orchards in dry and wet areas ( F = 12.29). The abundance of α‐Proteobacteria in the ureC microbial community composition was 24.24% higher in the wet areas compared to the dry areas, which was mainly determined by the increase in generalist‐abundant subcommunities in the wet areas. The co‐occurrence network for the ureC microbial community was more complex and stable in wet areas, and most keystone species in the network were abundant taxa. The natural connectivity of the subcommunities was 30.36% higher in the network for wet areas than dry areas. Our results provide the large‐scale evidence for the relative contribution of soil ureC microbial diversity, community structure, and network complexity to soil urease activity in the main apple production areas of China under different climates. Which has important significance for understanding the role of soil microorganisms in regulating nitrogen cycling under future environmental changes. Read the free Plain Language Summary for this article on the Journal blog.