Soil Bacterial and Fungal Richness and Network Exhibit Different Responses to Long-Term Throughfall Reduction in a Warm-Temperate Oak Forest

Jinglei Zhang,Xiaojing Liu,Junwei Luan,Shirong Liu,Xinwei Guo,Cuiju Liu,Hui Wang,Baoliang Niu

doi:10.3390/f12020165

Abstract

Prolonged drought results in serious ecological consequences in forest ecosystems, particularly for soil microbial communities. However, much is unknown about soil microbial communities in their response to long-term consecutive droughts in warm-temperate forests. Here, we conducted a 7-year manipulated throughfall reduction experiment (TFR) to examine the responses of bacterial and fungal communities in terms of richness and networks. Our results show that long-term TFR reduced bacterial, but not fungal, richness, with rare bacterial taxa being more sensitive to TFR than dominant taxa. The bacterial network under the TFR treatment featured a simpler network structure and fewer competitive links compared to the control, implying weakened interactions among bacterial species. Bacterial genes involved in xenobiotic biodegradation and metabolism, and lignin-degrading enzymes were enhanced under TFR treatment, which may be attributed to TFR-induced increases in fine root biomass and turnover. Our results indicate that soil bacterial communities are more responsive than fungi to long-term TFR in a warm-temperate oak forest, leading to potential consequences such as the degradation of recalcitrant organics in soil.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
The throughfall reduction (TFR) had no significant effects on soil chemical properties, including the pH, Soil organic C (SOC), total N (TN) and total P (TP) (Table S1)
Long-term experimental throughfall reduction (TFR) in a warm-temperate forest caused a reduction in bacterial richness but had little effect on fungal communities

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Microorganisms play essential roles as decomposers and provide crucial ecosystem functions such as soil carbon sequestration [1,2]. There is a challenge in understanding the responses of these highly diverse and complex microbial communities to extreme droughts, which are projected to continually increase in frequency and intensity in the future [3]. Previous studies that have mostly conducted short-term drought experiments have demonstrated considerable effects on soil microbial communities across different ecosystems [4,5]. We still know little about the impacts of long-term consecutive droughts on soil microbial communities and the potential functions they mediate [6], in warm-temperate forests

Methods

Results

Discussion

Conclusion