Rhizosphere Soil Microbial Properties on Tetraena mongolica in the Arid and Semi-Arid Regions, China.

Mengying Ruan,Yuxiu Zhang,Tuanyao Chai

doi:10.3390/ijerph17145142

Abstract

Tetraena mongolica is a rare and endangered species unique to China. The total number and density of Tetraena mongolica shrubs in desertification areas have experienced a sharp decrease with increases in coal mining activities. However, available information on the T. mongolica rhizosphere soil quality and microbial properties is scarce. Here, we investigated the effect of coal mining on the soil bacterial community and its response to the soil environment in the T. mongolica region. The results showed that the closer to the coal mining area, the lower the vegetation coverage and species diversity. The electrical conductivity (EC) in the contaminated area increased, while the total nitrogen (TN), available phosphorus (AP), available potassium (AK), and soil organic carbon (SOC) decreased. The activity of NAG, sucrose, β-glucosidase, and alkaline phosphatase further decreased. In addition, the mining area could alter the soil’s bacterial abundance and diversity. The organic pollutant degradation bacteria such as Sphingomonas, Gemmatimonas, Nocardioides, and Gaiella were enriched in the soil, and the carbon-nitrogen cycle was changed. Canonical correspondence analysis (CCA) and Pearson’s correlation coefficients showed that the change in the bacterial community structure was mainly caused by environmental factors such as water content (SWC) and EC. Taken together, these results suggested that open pit mining led to the salinization of the soil, reduction the soil nutrient content and enzyme activity, shifting the rhizosphere soil microbial community structure, and altering the carbon-nitrogen cycle, and the soil quality declined and the growth of T. mongolica was affected in the end. Therefore, the development of green coal mining technology is of great significance to protect the growth of T. mongolica.

Highlights

T. mongolica is a rare and endangered species unique to the western Ordos Plateau in North-Central and Wuhai City, China [1]
Canonical correspondence analysis (CCA) and Pearson’s correlation coefficients showed that the change in the bacterial community structure was mainly caused by environmental factors such as water content (SWC) and electrical conductivity (EC). These results suggested that open pit mining led to the salinization of the soil, reduction the soil nutrient content and enzyme activity, shifting the rhizosphere soil microbial community structure, and altering the carbon-nitrogen cycle, and the soil quality declined and the growth of
Our study showed that open pit mining had severe effects on Tetraena mongolica soil properties such as the SWC, soil EC, nutrient levels, and enzyme activities

Summary

Introduction

T. mongolica is a rare and endangered species unique to the western Ordos Plateau in North-Central and Wuhai City, China [1]. China Red Data Book lists this rare species as the second highest priority for conservation. It is a common deciduous shrub inhabiting arid and semi-arid regions. T. mongolica is a xerophyte with a well-developed root system that is suited to its habitat and able to cope with drought and other harsh natural conditions. It serves a role in stabilizing the sand in the region by promoting soil and water conservation and windbreaking. T. mongolica has been in decline in recent years. During the last 28 years, it has decreased 19.36% and covers less than 13.40 km2 ·a−1 [2]

Objectives

Methods

Results

Discussion

Conclusion