Correlated Biogeographic Variation of Magnesium across Trophic Levels in a Terrestrial Food Chain

Xiao Sun,Hongzhang Kang,Adam D Kay,Guofang Liu,Xuan Zhou,Gaston E Small,Shan Yin,Chunjiang Liu,David William Pond

doi:10.1371/journal.pone.0078444

Abstract

Using samples from eastern China (c. 25 – 41° N and 99 – 123° E) and from a common garden experiment, we investigate how Mg concentration varies with climate across multiple trophic levels. In soils, plant tissue (Oriental oak leaves and acorns), and a specialist acorn predator (the weevil Curculio davidi), Mg concentration increased significantly with different slopes from south to north, and generally decreased with both mean annual temperature (MAT) and precipitation (MAP). In addition, soil, leaf, acorn and weevil Mg showed different strengths of association and sensitivity with climatic factors, suggesting that distinct mechanisms may drive patterns of Mg variation at different trophic levels. Our findings provide a first step toward determining whether anticipated changes in temperature and precipitation due to climate change will have important consequences for the bioavailability and distribution of Mg in food chain.

Highlights

Magnesium (Mg) likely has important influences on terrestrial ecosystems because of its critical role in many physiological processes [1]
The difference between soil Mg and organism Mg increased at higher latitudes because the positive relationship between Mg concentration and latitude was steeper for soils than it was for leaves, weevils, or acorns (Fig. 2; Table S3)
We document three main patterns: Mg concentration varies significantly with latitude in soil and in organisms at different trophic levels; patterns of variation differ among trophic levels such that soil and organism Mg are more divergent at higher latitudes, and environmental correlates of Mg variation differ to some extent for soils, leaves, acorns, and acorn predators

Summary

Introduction

Magnesium (Mg) likely has important influences on terrestrial ecosystems because of its critical role in many physiological processes [1]. Mg availability likely varies across abiotic gradients It may vary with precipitation because Mg has a high hydrated radius that sorbs less to colloids than other cations [8], making it highly prone to leaching. It may vary with temperature, which generally affects nutrient mineralization rates [9]. Understanding the relationships between Mg in plants and consumers across abiotic gradients should provide important new information about physiological and ecological ramifications of mineral nutrients in terrestrial ecosystems

Methods

Results

Discussion

Conclusion