Litter quality drives the differentiation of microbial communities in the litter horizon across an alpine treeline ecotone in the eastern Tibetan Plateau

Haifeng Zheng,Yamei Chen,Lifeng Wang,Jian Zhang,Hongjie Li,Wanqing Yang,Lin Yang,Yang Liu,Li Guo,Fuzhong Wu

doi:10.1038/s41598-018-28150-1

Haifeng Zheng, Yamei Chen + Show 8 more

Open Access

https://doi.org/10.1038/s41598-018-28150-1

Copy DOI

Abstract

Cellulose and lignin are the main polymeric components of the forest litter horizon. We monitored microbial community composition using phospholipid fatty acid (PLFA) analysis and investigated the ligninolytic and cellulolytic enzyme activities of the litter horizon across an alpine treeline ecotone in the eastern Tibetan Plateau. The activities of ligninolytic and cellulolytic enzymes and the biomass of microbial PLFAs were higher in the initial stage of litter decomposition than in the latter stage in the three vegetation types (coniferous forest, alpine shrubland and alpine meadow). Soil microbial community structure varied significantly over the course of litter decomposition in the three vegetation types. Furthermore, the BIOENV procedure revealed that the carbon to nitrogen (C:N) ratio, carbon to phosphorus (C:P) ratio and moisture content (MC) were the most important determinants of microbial community structure in the initial stage of litter decomposition, whereas pH and the lignin concentration were the major factors influencing the microbial community structure in the later stage of litter decomposition. These findings indicate that litter quality drives the differentiation of microbial communities in the litter horizon across an alpine treeline ecotone in the eastern Tibetan Plateau.

Highlights

The decomposition of plant litter involves a complex set of processes that include chemical, physical, and biological agents acting upon a wide variety of organic substrates
Moisture content and pH were lower in the litter and fermentation (LF) layer than in the H layer in alpine meadow (p < 0.05, Table 1). pH was higher in the LF layer than in the H layer in coniferous forest (p < 0.05, Table 1)
Our results indicated that the activities of ligninolytic enzymes (LiP and manganese peroxidase (MnP)) and cellulolytic enzymes (EG and BG) as well as the biomass of microbial phospholipid fatty acid (PLFA) (TB, total fungi (TF), G+, G− and MB) were higher during the initial stage of litter decomposition in the three vegetation types

Summary

Introduction

The decomposition of plant litter involves a complex set of processes that include chemical, physical, and biological agents acting upon a wide variety of organic substrates. The L layer is the upper layer and is formed by recognizable plant and soil animal remains This layer is a layer that typically consists of a mixture of organic matter in different stages of decomposition, known as the F layer. Due to the differences among the different stages of litter decomposition in chemical properties and available carbon for microorganisms, we hypothesized that lignocellulolytic enzyme activity and microbial community structure are constantly changing during the different stages of litter decomposition. Our objectives were to answer two questions: (1) How do lignocellulolytic enzyme activities, microbial PLFA biomasses and community structure differ between the two litter decomposition stages for the three vegetation types? (2) How do the relationships between litter physicochemical properties (e.g., soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP)) and microbial community structure differ between the two litter decomposition stages? Our objectives were to answer two questions: (1) How do lignocellulolytic enzyme activities, microbial PLFA biomasses and community structure differ between the two litter decomposition stages for the three vegetation types? (2) How do the relationships between litter physicochemical properties (e.g., soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP)) and microbial community structure differ between the two litter decomposition stages?

Objectives

Methods

Results

Discussion

Conclusion