Single-Species Artificial Grasslands Decrease Soil Multifunctionality in a Temperate Steppe on the Qinghai–Tibet Plateau

Kelu Chen,Huakun Zhou,Sha Xue,Jie Wang,Yang Wu,Mei Wang,Yuanze Li,Wenjing Chen,Guobin Liu,Yue Zhang,Bingbing Lu,Ziwen Zhao

doi:10.3390/agronomy11112092

Abstract

Artificial grasslands have been regarded as an effective method to improve grass production and quality, especially on the Qinghai–Tibet Plateau. Soil ecosystem multifunctionality (EMF) plays an important role in sustainable regional development. However, few studies have investigated the impacts of artificial grasslands on soil EMF. Here, we constructed single-species artificial grasslands in a natural temperate steppe and investigated soil microbial communities, abiotic factors (soil moisture and pH), and functions related to biogeochemical cycles to explore (1) how the transformation from temperate steppe to artificial grasslands affected soil EMF and (2) the roles of species and phylogenetic microbial diversities, microbial community composition, and abiotic factors in driving differences in soil EMF. Our results showed that artificial grasslands decreased soil EMF regardless of planting species; that the bacterial and fungal community composition contributed more to soil EMF prediction than species and phylogenetic diversities; and that microbial phylogenetic diversities were negatively associated with soil EMF. Soil pH played an important role in the effects of artificial grasslands on soil EMF—artificial grasslands increased soil pH, which was negatively associated with soil EMF. Overall, the benefits of establishing artificial grasslands, for example, higher grass production and quality, might be at the expense of soil EMF. Further studies should explore mixed-species artificial grasslands.

Highlights

All the above single functions of the temperate steppe were decreased by artificial grasslands
Artificial grasslands are regarded as a feasible method to improve grass production and quality [42], our results showed that they decreased soil ecosystem multifunctionality (EMF), which is important for sustainable development [43], compared with natural temperate steppes
Artificial grasslands that are harvested could have lower soil nutrient inputs and increase soil pH [25,45], which might inhibit the soil microorganisms being adaptive to acidified condition and possibly decrease soil functions

Summary

Introduction

Grasslands are a major vegetation type on the Qinghai–Tibet Plateau; they provide many vital ecological functions, such as carbon storage, water and soil conservation, and animal habitat [1,2]. Artificial grasslands have been constructed because of their higher production and quality compared with natural grasslands [3]. In addition to their effects on vegetation, artificial grasslands impact multiple soil and ecosystem functions, with their impact varying depending on the species planted [4,5,6]. Investigating multiple ecological functions together, rather than focusing on individual functions, could help us comprehensively predict the ecological efficiency of artificial grasslands and determine optimal planting species [7]

Methods

Results

Discussion

Conclusion