Data from: Decreasing stoichiometric resource quality drives compensatory feeding across trophic levels in tropical litter invertebrate communities

Living organisms are constrained by both resource quantity and quality. Ecological stoichiometry offers important insights into how the elemental composition of resources affects their consumers. If resource quality decreases, consumers can respond by shifting their body stoichiometry, avoiding low-quality resources, or through up-regulation of feeding rates to maintain the supply of required elements while excreting the excess carbon (i.e., compensatory feeding). We analysed multitrophic consumer body stoichiometry, biomass and feeding rates along a resource-quality gradient in the litter of tropical forest, rubber and oil-palm plantations. Specifically, we calculated macro-invertebrate feeding rates based on consumer metabolic demand and assimilation efficiency. Using linear mixed effects models, we assessed resource-quality effects on macro-invertebrate detritivore and predator communities. We did not detect shifts in consumer body stoichiometry or decreases in consumer biomass in response to declining resource quality, as indicated by increasing C:N ratios. However, across trophic levels, we found a strong indication of decreasing resource quality leading to increased consumer feeding rates through altered assimilation efficiency and community body size structure. Our study reveals the influence of resource quality on multitrophic consumer feeding rates and suggests compensatory feeding to be more common across consumer trophic levels than was formerly known.

生物同时受资源数量与资源质量的双重约束。生态化学计量学（Ecological Stoichiometry）为揭示资源元素组成如何影响其消费者提供了重要视角。当资源质量下降时，消费者可通过调整自身化学计量组成、避开低质量资源，或上调取食速率以维持必需元素的供给同时排出过量碳（即补偿取食，compensatory feeding）。本研究沿热带森林、橡胶林与油棕种植园的凋落物资源质量梯度，分析了多营养级消费者的体化学计量特征、生物量及取食速率。具体而言，本研究基于消费者的代谢需求与同化效率，计算了大型无脊椎动物（macro-invertebrate）的取食速率。采用线性混合效应模型（Linear Mixed Effects Models），本研究评估了资源质量对大型无脊椎动物腐食性动物（detritivore）与捕食性动物（predator）群落的影响。结果显示，随着碳氮比（C:N）升高所反映的资源质量下降，消费者的体化学计量未发生改变，消费者生物量也未出现下降。然而，在各营养级中，本研究发现资源质量下降可通过改变同化效率与群落体型结构，显著提升消费者的取食速率，该效应具有强统计学指示意义。本研究揭示了资源质量对多营养级消费者取食速率的调控作用，并表明补偿取食在消费者各营养级中的普遍性远超此前认知。