Data from: Woodstoich III: integrating tools of nutritional geometry and ecological stoichiometry to advance nutrient budgeting and the prediction of consumer-driven nutrient recycling

Within the last two decades, ecological stoichiometry (ES) and nutritional geometry (NG, also known as geometric framework for nutrition) have delivered novel insights into core questions of nutritional ecology. These two nutritionally explicit frameworks differ in the ‘nutrient currency’ used and the focus of their past research; behavioural feeding strategies in NG, mainly investigating terrestrial organisms, and trophic ecology in ES, mainly in aquatic settings. However, both NG and ES have developed in explaining patterns across various scales of biological organization. Integrating specific tools of these frameworks could advance the field of nutritional ecology by unifying theoretical and empirical approaches from the organismal to ecosystem level processes. Toward this integration, we identified 1) nutrient/element budgets as a shared concept of both frameworks that encompass nutrient intake, retention, and release, 2) response surface plots of NG as powerful tools to illustrate processes at the organismal level and 3) the concept of consumer-driven nutrient recycling (CNR) of ES as a useful tool bridging organism and ecosystem scales. We applied response surface plots to element budget data from an ES study to show how this approach can deliver new insights at the organismal level, e.g. by showing the interplay between egestion and excretion depending simultaneously on the consumed amount of carbon and phosphorus based on variation across individuals. By integrating concepts of ES and NG to model microbial uptake and mineralization of nitrogenous wastes reported in a NG study, we also demonstrate that considering biochemically explicit mineralization rates of organic wastes can improve predictions of CNR by reducing over- or underestimation of mineralization depending on the quality of the consumer's diet. Our presented tools and approaches can help to bridge the organismal and ecosystem level, advancing the predictive power of studies in nutritional ecology at multiple ecological scales.

近二十年来，生态化学计量学（ecological stoichiometry, ES）与营养几何学（nutritional geometry, NG，亦称营养几何框架）为营养生态学的核心议题带来了全新认知。这两类以营养为核心的研究框架，在所用的营养计量基准以及既往研究侧重点上存在差异：NG主要关注摄食行为策略，研究对象多为陆生生物；而ES则聚焦营养级生态学，研究场景多集中于水生环境。不过，二者均在阐释不同生物组织层级的生态规律方面取得了长足发展。整合这两类框架的特定工具，有望统一从个体到生态系统层面的理论与实证研究方法，从而推动营养生态学领域的进步。为实现这一整合目标，我们明确了三类共通内容：1）营养/元素收支是二者的共有概念，涵盖营养的摄入、留存与释放；2）NG的响应面图可作为阐释个体层面生态过程的有力工具；3）ES的消费者驱动营养循环（consumer-driven nutrient recycling, CNR）概念，是连接个体与生态系统层级的实用工具。我们将响应面图应用于一项ES研究的元素收支数据，以此展示该方法如何在个体层面带来新的研究视角——例如，通过分析个体间的差异，揭示碳与磷摄入量共同调控排粪与排泄之间的相互作用关系。此外，我们结合ES与NG的概念，对一项NG研究中报道的微生物摄取与含氮废物矿化过程进行建模，结果证实：考虑有机废物的生化特异性矿化速率，可根据消费者日粮质量调整矿化预测的偏差，减少过度估算或低估的情况，从而优化消费者驱动营养循环的预测效果。本文提出的工具与研究方法，有助于打通个体与生态系统层级的研究壁垒，提升多生态尺度下营养生态学研究的预测能力。