Response of Bacterial and Fungal Soil Communities to Chinese Fir (Cunninghamia lanceolate) Long-Term Monoculture Plantations.

Xian Liu,Yuhui Liu,Hui Chen,Yalin Hu,Yuzhe Wang

doi:10.3389/fmicb.2020.00181

Xian Liu, Yuhui Liu + Show 3 more

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https://doi.org/10.3389/fmicb.2020.00181

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Abstract

Successive rotation and monoculture, as common silvicultural practices, are extensively applied worldwide, particularly in subtropical Chinese fir (Cunninghamia lanceolata) plantations in southern China. Although regeneration failure and productivity decline are frequently observed in continuous monoculture plantations, the potential mechanisms are still unclear. In this study, high-throughput sequencing was used to compare the diversity and composition of bacterial and fungal communities among different generations of Chinese fir plantation (first rotation, FRP; second rotation, SRP; third rotation, TRP) and natural forest (NF) in December and June. Our results showed significant declines in richness and diversity of bacterial and fungal communities in TRP compared with FRP and SRP, but no significant difference between FRP and SRP. The fungal phyla with high relative abundance were Basidiomycota (12.9–76.9%) and Ascomycota (14.3–52.8%), while the bacterial phyla with high relative abundance were Acidobacteria (39.1–57.7%) and Proteobacteria (21.2–39.5%) in all treatments at both sampling months. On average, the relative abundance of Basidiomycota in TRP increased by 53.4%, while that of Ascomycota decreased by 37.1% compared with FRP and SRP. Moreover, soil NH4+–N, pH, and DOC appear to be the key factors in shaping the fungal communities, while soil NH4+–N, DOCN, and AP primarily drive the changes in bacterial communities. Collectively, our findings highlighted the alteration of soil bacterial and fungal communities induced by changes in soil nutrient environment in different generations of continuously cultivated Chinese fir plantation.

Highlights

Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] is one of the most important plantations in subtropical China due to its high yield and good timber quality
Significant higher pH was observed in second rotation plantation (SRP) compared with fir rotation plantation (FRP) and third rotation plantation (TRP), and no significant difference was observed between FRP and TRP at both sampling times (Table 1) (P < 0.05)
In December, the SRP had significant higher soil moisture compared with FRP and TRP, while no significant difference was found between FRP and TRP (Table 1) (P < 0.05)

Summary

Introduction

Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] is one of the most important plantations in subtropical China due to its high yield and good timber quality. Since the 1950s, the area of Chinese fir plantation has been greatly enlarged, in order to meet the rising demand for timber caused by economic development and population increase in China. Bacterial and Fungal Community Structures silvicultural practices for Chinese fir, including monoculture, continuous plantation, and shortened rotation time of 20 years (Wang et al, 2005), have led to multiple ecological problems such as soil nutrient depletion and timber productivity decline (Ma et al, 2007; Liu et al, 2010; Tian et al, 2011). Comprehensive and in-depth study into soil microbial community and the mechanisms involved in soil–microbe interactions in Chinese fir plantations is still lacking

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