The Joint Contributions of Environmental Filtering and Spatial Processes to Macroinvertebrate Metacommunity Dynamics in the Alpine Stream Environment of Baima Snow Mountain, Southwest China

Nima Cili,Shuoran Liu,Ronglong Yang,Wen Xiao,Davide Fornacca,Lu Tan,Zhen Tian,Yanpeng Li,Zhengfei Li,Muhammad Farooq,Xianfu Li,Zhongyong Ciren

doi:10.3390/d14010028

Abstract

While macroinvertebrates are extensively investigated in many river ecosystems, meta-community ecology perspectives in alpine streams are very limited. We assessed the role of ecological factors and temporal dynamics in the macroinvertebrate meta-community assembly of an alpine stream situated in a dry-hot valley of Baima Snow Mountain, China. We found that spatial structuring and environmental filtering jointly drive the structure of macroinvertebrate meta-community, with relative contributions to the variance in community composition changing over time. RDA ordination and variation partitioning indicate that environmental variables are the most important predictors of community organization in most scenarios, whereas spatial determinants also play a significant role. Moreover, the explanatory power, identity, and the relative significance of ecological factors change over time. Particularly, in the years 2018 and 2019, stronger environmental filtering was found shaping community assembly, suggesting that deterministic mechanisms predominated in driving community dynamics. However, spatial factors had a stronger predictive power on meta-community structures in 2017, implying conspicuous dispersal mechanisms which may be owing to increased connectivity amongst sites. Thereby, we inferred that the alpine stream macroinvertebrate metacommunity composition can be regulated by the interaction of both spatial processes and environmental filtering, with relative contributions varying over time. Based on these findings, we suggest that community ecology studies in aquatic systems should be designed beyond single snapshot investigations.

Highlights

Licensee MDPI, Basel, Switzerland.Understanding the fundamental processes that drive spatio-temporal changes in biological communities is one of the most pressing topics in community ecology
The first three principal components (PC) explained 91.53% of the variation, the local environmental factors such as conductivity, water temperature, dissolved oxygen, hydrogen ion concentration, salinity, and total dissolved solids were positively correlated on the first principle component, while altitude and oxidation-reduction potential were negatively correlated
The second axis (PC2) explained 31.21% of the variation was mainly associated with water temperature, dissolved oxygen, and hydrogen ion concentration

Summary

Introduction

Licensee MDPI, Basel, Switzerland.Understanding the fundamental processes that drive spatio-temporal changes in biological communities is one of the most pressing topics in community ecology. Apart from this, stochastic processes presume that there is no ecological differentiation among species, and spatial characteristics are considered essential in constructing community assembly [5]. Meta-community ecology is one of the most intensively growing fields of community ecology, which provides an effective framework for studying community assembly mechanisms by integrating numerous ecological events, such as dispersal-linked and niche-based processes [6]. This points to the fact that local communities are driven by local-scale environmental variables and by regional-scale spatial factors [7]

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