Soil Microbial Community Assembly and Interactions Are Constrained by Nitrogen and Phosphorus in Broadleaf Forests of Southern China

Jingmin Cheng,Mengxin Zhao,Jizhong Zhou,Kristen N Wyckoff,Hui Lu,Diqiang Li,Qi Qi,Jing Cong,Daliang Ning,Yuguang Zhang,Yuyu Sheng,Ye Deng

doi:10.3390/f11030285

Abstract

Subtropical and tropical broadleaf forests play important roles in conserving biodiversity and regulating global carbon cycle. Nonetheless, knowledge about soil microbial diversity, community composition, turnover and microbial functional structure in sub- and tropical broadleaf forests is scarce. In this study, high-throughput sequencing was used to profile soil microbial community composition, and a micro-array GeoChip 5.0 was used to profile microbial functional gene distribution in four sub- and tropical broadleaf forests (HS, MES, HP and JFL) in southern China. The results showed that soil microbial community compositions differed dramatically among all of four forests. Soil microbial diversities in JFL were the lowest (5.81–5.99) and significantly different from those in the other three forests (6.22–6.39). Furthermore, microbial functional gene interactions were the most complex and closest, likely in reflection to stress associated with the lowest nitrogen and phosphorus contents in JFL. In support of the importance of environmental selection, we found selection (78–96%) dominated microbial community assembly, which was verified by partial Mantel tests showing significant correlations between soil phosphorus and nitrogen content and microbial community composition. Taken together, these results indicate that nitrogen and phosphorus are pivotal in shaping soil microbial communities in sub- and tropical broadleaf forests in southern China. Changes in soil nitrogen and phosphorus, in response to plant growth and decomposition, will therefore have significant changes in both microbial community assembly and interaction.

Highlights

Forests play important roles in biodiversity conservation, providing a variety of critical resources and ecosystem services to humans, and generally serve as carbon sinks [1]
Soil microbial taxonomic compositions and functional gene structures involved in carbon and
Soil microbial taxonomic compositions and functional gene structures involved in carbon and nitrogen cycling in four broadleaf forests in China were determined

Summary

Introduction

Forests play important roles in biodiversity conservation, providing a variety of critical resources and ecosystem services to humans, and generally serve as carbon sinks [1]. Subtropical and tropical forests, which contain up to 55% of global carbon stocks, dominate southern China and have favorable climatic conditions with regard to temperature, light and water [1]. Due to these advantageous climatic conditions, the region has high biodiversity in plants and animals [2]. Soil microbial information in subtropical and tropical forests of southern China, is relatively scarce, despite their important ecological functions in driving biogeochemical elemental cycles [3]. Soil microbial community composition and diversity in sub- and tropical forests are subjected to influence from land-use changes [6,7]. It is a crucial to conduct a baseline study to document soil microbial biogeography in sub- and tropical forests, which is a prerequisite for understanding microbial responses to environmental changes and their ecological consequences

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Conclusion