Soil pH, total phosphorus, climate and distance are the major factors influencing microbial activity at a regional spatial scale.

Haichuan Cao,Shixue Zheng,Xiangui Lin,Fen Yang,Gejiao Wang,Ruirui Chen,Libing Wang,Lanlan Jiang

doi:10.1038/srep25815

Abstract

Considering the extensive functional redundancy in microbial communities and great difficulty in elucidating it based on taxonomic structure, studies on the biogeography of soil microbial activity at large spatial scale are as important as microbial community structure. Eighty-four soil samples were collected across a region from south to north China (about 1,000 km) to address the questions if microbial activity displays biogeographic patterns and what are driving forces. These samples represented different soil types, land use and climate. Redundancy analysis and nonmetric multidimensional scaling clearly revealed that soil microbial activities showed distinct differentiation at different sites over a regional spatial scale, which were strongly affected by soil pH, total P, rainfall, temperature, soil type and location. In addition, microbial community structure was greatly influenced by rainfall, location, temperature, soil pH and soil type and was correlated with microbial activity to some extent. Our results suggest that microbial activities display a clear geographic pattern that is greatly altered by geographic distance and reflected by climate, soil pH and total P over large spatial scales. There are common (distance, climate, pH and soil type) but differentiated aspects (TP, SOC and N) in the biogeography of soil microbial community structure and activity.

Highlights

Microorganisms are at least as important as their biodiversity pattern in the biogeochemical studies
It is widely assumed that the soil microbial function is determined primarily by the environmental factors, some studies showed that biochemical function was related to community composition of microbes in soil at a local scale, and both microbial community structure and their function were influenced by soil pH, temperature, moisture and nutrient availability[3,16,21,22]
From south to north area, mean annual temperature (MAT) and mean annual rainfall (MAR) gradually decreased, whereas soil pH increased except the soil pH in Wuhan at central China varying greatly

Summary

Introduction

Microorganisms are at least as important as their biodiversity pattern in the biogeochemical studies. Soil fungi were endemic to bioregions, whereas soil extracellular enzyme activity showed stochastic pattern[3] This suggests that microbial function can be as similar as geographic pattern of diversity and composition, and dissimilar influences of historical events versus environmental factors are related to the sampling effort or spatial scale[23]. We collected 84 soil samples across a regional scale (about 1,000 km) in China, covering different soil type, climate, vegetation, and chemical properties We build such a system to examine (1) our hypothesis that soil microbial activity displays biogeographic patterns at large spatial scales, (2) the controlling factor of microbial activity, e.g. historical events and environmental factors, and (3) how common microbial community structure and function are linked

Methods

Results

Conclusion