AM Fungi Endow Greater Plant Biomass and Soil Nutrients under Interspecific Competition Rather Than Nutrient Releases for Litter

Bangli Wu,Kaiping Shen,Lipeng Zang,Xu Han,Minhong He,Tingting Xia,Qingfu Liu,Liling Kang,Danmei Chen,Yun Guo,Yuejun He

doi:10.3390/f12121704

Abstract

Plant competition affects belowground ecological processes, such as litter decomposition and nutrient release. Arbuscular mycorrhizal (AM) fungi play an essential role in plant growth and litter decomposition potentially. However, how plant competition affects the nutrient release of litter through AM fungi remains unclear especially for juvenile plants. In this study, a competitive potting experiment was conducted using juvenile seedlings of Broussonetia papyrifera and Carpinus pubescens from a karst habitat, including the intraspecific and interspecific competition treatments. The seedlings were inoculated by AM fungus or not inoculated, and the litter mixtures of B. papyrifera and C. pubescens were added into the soil or not added. The results were as follows: Litter addition significantly increased the root mycorrhizal colonization of two species in intraspecific competition. AM fungus significantly increased the biomass of B. papyrifera seedings and nitrogen release and decreased nitrogen concentration and N/P ratio of litter and further improved the total nitrogen and N/P ratio of soil under litter. The interspecific competition interacting with AM fungus was beneficial to the biomass accumulation of B. papyrifera and improvement of soil nutrients under litter. However, intraspecific competition significantly promoted nutrient releases via AM fungus. In conclusion, we suggest that AM fungi endow greater plant biomass and soil nutrients through interspecific competition, while intraspecific competition prefers to release the nutrients of litter.

Highlights

Litter is an essential carrier for carbon storage and nutrient cycling in terrestrial ecosystems [1] and is the main source of nutrients that flow into the soil through decomposition and nutrient release [2], which is closely related to the aboveground and belowground ecological process [3]
The interspecific competition significantly increased the biomass of B. papyrifera than the intraspecific competition via Arbuscular mycorrhizal (AM) fungus regardless of litter addition (Figure 2a,c), which indicated that interspecific competition endowed plant biomass accumulation an advantage over the intraspecific competition
The litter addition had a significant improvement on the root mycorrhizal colonization of B. papyrifera and C. pubescens in intraspecific competition

Summary

Introduction

Litter is an essential carrier for carbon storage and nutrient cycling in terrestrial ecosystems [1] and is the main source of nutrients that flow into the soil through decomposition and nutrient release [2], which is closely related to the aboveground and belowground ecological process [3]. Most plants return to the soil in the form of litter, which provides substantial nutrients and energy for the soil [3,8]. This process is affected by soil microorganisms, which are considered to be the major drivers of biogeochemical cycles [9,10,11]

Objectives

Results

Discussion

Conclusion