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

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.

本研究以中国东部（北纬25°–41°、东经99°–123°）的样品及同质园实验（common garden experiment）样本为材料，探究多营养级水平下镁（Magnesium, Mg）浓度随气候因子的变化规律。在土壤、植物组织（东方栎叶片与橡子）以及专食橡子的捕食者——象鼻虫（Curculio davidi）体内，镁浓度随纬度梯度（自南向北）呈现显著上升的变化趋势，且随年平均气温（Mean Annual Temperature, MAT）与年平均降水量（Mean Annual Precipitation, MAP）的增加整体呈下降态势。此外，土壤、叶片、橡子及象鼻虫体内的镁浓度与气候因子的关联强度及响应敏感度均存在显著差异，这表明不同营养级的镁浓度变化格局可能由不同的调控机制所驱动。本研究结果为厘清气候变化引发的气温与降水预期变化是否会对食物链中镁元素的生物有效性与空间分布产生重要影响迈出了第一步。