Profiling the Bacterial Diversity in a Typical Karst Tiankeng of China.

Longwu Zhou,Danjuan Zeng,Gaozhong Pu,Guangping Xu,Lina Dong,Ling Mo,Yanna Lv,Kechao Huang

doi:10.3390/biom9050187

Longwu Zhou, Danjuan Zeng + Show 6 more

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https://doi.org/10.3390/biom9050187

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Abstract

While karst tiankengs have a higher capacity to act as safe havens for biodiversity in changing climates, little is known about their soil microorganisms. To fill this gap, we investigate the distribution and driving factors of the bacterial community in karst tiankeng systems. There is a significant difference in the soil characteristics between the inside and the outside of a karst tiankeng. At the karst tiankeng considered in this study, the bacterial composition, in terms of the operational taxonomic unit (OTU), was found to be significantly different in different soil samples, taken from diverse sampling sites within the collapsed doline or the external area, and showed a high habitat heterogeneity. The dominant phylum abundances vary with the sampling sites and have their own indicator taxa from phylum to genus. Unlike the primary controlling factors of plant diversity, the microclimate (soil moisture and temperature), soil pH, and slope dominated the distribution of the bacterial community in karst tiankeng systems. Our results firstly showed the distribution characteristics of bacterial communities and then revealed the importance of microhabitats in predicting the microbial distribution in karst tiankeng systems.

Highlights

IntroductionOngoing anthropogenic disturbances (such as climate change) are considered to pose a potential threat to the distribution of plant species and ecosystems processes [1]
Ongoing anthropogenic disturbances are considered to pose a potential threat to the distribution of plant species and ecosystems processes [1]
Compared with the steep slope site of the inside tiankeng (ES) and outside tiankeng sites (OST), from the small gradient slope sites (e.g., the bottom central of the Shenmu tiankeng (BC), the middle slope of the Shenmu tiankeng (MS), and US), the collected soil samples were characterized by black humus soil (Table A1), higher total organic carbon (TOC), total nitrogen (TN), and Ca concentrations, but lower concentrations of major elements (K, Mg, and Fe)

Summary

Introduction

Ongoing anthropogenic disturbances (such as climate change) are considered to pose a potential threat to the distribution of plant species and ecosystems processes [1]. Due to their special environmental characteristics, refugia could provide stable habitats for plant species and protect them from the negative effects of environmental changes [2,3]. Previous studies have shown that refugia, especially karst tiankengs (a kind of important modern refugia) preserved more old-growth and endemic plant species than the degraded habitats outside tiankeng, and had a higher capacity to act as safe havens for biodiversity in changing climates [3,4,5]. Due to the trapping of surrounding rock walls and terrain constraints, the outside and inside habitats of tiankengs are Biomolecules 2019, 9, 187; doi:10.3390/biom9050187 www.mdpi.com/journal/biomolecules

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