Linkage between microbial functional genes and net N mineralisation in forest soils along an elevational gradient

作者：Jieying Wang, Liyuan He, Xiaofeng Xu, Chengjie Ren, Jun Wang, Yaoxin Guo, Fazhu Zhao · 发表于：European Journal of Soil Science · 年份：2022 · DOI：10.1111/ejss.13276 · 被引用次数：20 · 研究领域：Soil Carbon and Nitrogen Dynamics、Microbial Community Ecology and Physiology、Genomics and Phylogenetic Studies

Abstract Soil net nitrogen (N) mineralisation, the difference between organic nitrogen mineralisation and mineral nitrogen immobilisation, changes with elevation, thereby determining plant productivity and soil N cycling along elevation gradients. However, it has yet to be established how different microbial functional genes influence the rate of soil net N mineralisation along such gradients. To address this deficiency in our current knowledge, we performed metagenomic sequencing to identify soil microbial functional genes encoding enzymes involved in N cycling at five forest sites along an elevational gradient spanning a range from 1503 to 3182 m above sea level. Our results indicate that the rate of net N mineralisation follows a unimodal pattern with increasing elevation, with a peak (0.18 mg kg −1 d −1 ) being detected at the mid‐high elevation site. Further, we detected a significant correlation between the abundance of genes encoding enzymes involved in denitrification and ammonia assimilation pathways and net N mineralisation rate ( p < 0.05). Moreover, we established that microbial species in the phyla Cyanobacteria , Acidobacteria and Planctomycetes , harbouring keystone functional genes, play a predominant role in determining the rate of net N mineralisation. Our findings also revealed soil substrate content (ammonium nitrogen and nitrite nitrogen, soil organic carbon, and C:N ratio) and soil environment (soil temperature and soil moisture) to be the major drive...