Soil Mesofauna Respond to the Upward Expansion of Deyeuxia purpurea in the Alpine Tundra of the Changbai Mountains, China.

Yan Tao,Yinghua Jin,Chen Ma,Xiaoxue Zheng,Jiawei Xu,Zhongqiang Wang,Hongshi He,Haixia Wang

doi:10.3390/plants8120615

Abstract

Deyeuxia purpurea, a low-altitude species, has been expanding upwards into alpine tundra, and this upward expansion is causing serious ecological consequences. However, few studies have been performed regarding its effects on soil faunal communities. We examine how the upward expansion of D. purpurea affects the abundance, richness, and diversity of soil mesofauna, and evaluate how different taxa of soil mesofauna respond to the upward expansion of D. purpurea in the alpine tundra of Changbai Mountains, northeast China. A total of 128 soil mesofaunal samples were collected from four treatments, namely high upward expansion (HU), medium upward expansion (MU), low upward expansion (LU), and native plant habitats (NP). The results revealed that the abundance of soil mesofauna was increased with the rise of D. purpurea upward expansion, and the taxonomic composition varied with the different levels of D. purpurea upward expansion in the alpine tundra of the Changbai Mountains. No unique taxa were collected in the native plant habitats, and the upward expansion of D. purpurea promoted the colonization of predatory invertebrates. Isotomidae and Gamasida responded positively to the herbaceous plant upward expansion, and thus they were considered to be a positive indicator of upward expansion. Hypogastruridae and Enchytraeidae responded relatively negatively, while Oribatida, Actinedida, and Pseudachorutidae had ambivalent responses to the upward expansion. Overall, the abundance of soil mesofauna can indicate the levels of the upward expansion of D. purpurea. Soil mesofaunal guild characteristics were altered by the upward expansion. The different taxa of soil mesofauna responded to herbaceous plants’ upward expansion to various degrees. Therefore, this study provide evidence supporting the fact that the abundance of soil mesofauna can indicate the levels of upward expansion of D. purpurea, but the responses of soil mesofauna to the upward expansion of D. purpurea differ among their taxa.

Highlights

Alpine tundra, which is characterized by low temperatures and high altitude, is a relatively harsh type of ecological system [1]
The Venn diagram and clustering analysis showed that there was a dissimilarity in the soil mesofaunal taxonomic compositions among the different treatments (Figures 1b and 3). These results indicate that the soil mesofaunal taxonomic compositions are affected by D. purpurea upwardly expanding in the alpine tundra of the Changbai Mountains
Due to the rise of phytophagous and saprophagous invertebrates, Gamasida’s abundance was increased, and it was considered to be a positive indicator of herbaceous plant upward expansion in the alpine tundra of the Changbai Mountains

Summary

Introduction

Alpine tundra, which is characterized by low temperatures and high altitude, is a relatively harsh type of ecological system [1]. Alpine plants have adapted to the harsh conditions of the tundra by surviving low temperature extremes, changing photosynthesis and respiration rates, avoiding ultraviolet radiation, and defending against desiccation [4,5]. It is difficult for low-altitude plants to adapt to alpine tundra enlivenments, and risks of upward expansion are relatively low [6]. Most studies regarding low-altitude plants expanding upward into alpine tundra have mainly focused on aboveground systems, e.g., evaluating changes of vegetation cover and estimating the plant communities’ diversity, whereas a relatively small number of studies have been performed regarding the effects of low-altitude plants’ upward expansion on belowground ecosystems

Methods

Results

Discussion

Conclusion