Data from: Simultaneous exposure to a pulsed and a prolonged anthropogenic stressor can alter consumer multifunctionality

Ecosystems face multiple anthropogenic threats globally, and the effects
of these environmental stressors range from individual-level organismal
responses to altered system functioning. Understanding the combined
effects of stressors on process rates mediated by individuals in
ecosystems would greatly improve our ability to predict organismal
multifunctionality (e.g. multiple consumer-mediated functions). We
conducted a laboratory experiment to test direct and indirect, as well as
immediate and delayed effects of a heat wave (pulsed stress) and
micropollutants (MPs) (prolonged stress) on individual consumers (the
great pond snail Lymnaea stagnalis) and their multifunctionality (i.e.
consumption of basal resources, growth, reproduction, nutrient excretion
and organic-matter cycling). We found that stressful conditions increased
the process rates of multiple functions mediated by individual consumers.
Specifically, the artificial heat wave increased process rates in the
majority of the quantified functions (either directly or indirectly),
whereas exposure to MPs increased consumption of basal resources which
lead to increases in the release of nutrients and fine particulate organic
matter. Moreover, snails exposed to a heat wave showed decreased
reproduction and nutrient excretion after the heat-wave, indicating the
potential for ecologically relevant delayed effects. Our study indicates
that the immediate and delayed effects of stressors on individual
organisms may directly and indirectly impact multiple ecosystem functions.
In particular, delayed effects of environmental stress on individual
consumers may cumulatively impede recovery due to decreased functioning
following a perturbation. Reconciling these results with studies
incorporating responses at higher levels of biological complexity will
enhance our ability to forecast how individual responses upscale to
ecosystem multifunctionality.

全球范围内，生态系统面临多重人为胁迫威胁，这些环境应激因子的影响跨度从个体水平的生物响应，直至生态系统整体功能的改变。厘清胁迫因子对生态系统中个体所介导的过程速率的联合效应，将大幅提升我们预测生物多功能性（例如多种消费者介导的生态功能）的能力。本研究开展了一项室内实验，旨在探究热浪（脉冲式胁迫）与微污染物（micropollutants，MPs）对个体消费者——大静水椎实螺（Lymnaea stagnalis）及其多功能性的直接、间接、即时与延迟效应。该实验所涉及的多功能性包括：基础资源摄食、生长、繁殖、营养盐排泄与有机质循环。研究结果显示，胁迫环境会提升个体消费者所介导的多项功能的过程速率。具体而言，人工热浪在绝大多数量化检测的功能中（无论直接或间接途径）提升了过程速率；而暴露于微污染物的个体则增加了基础资源的摄食量，进而推动了营养盐释放与细颗粒有机质的生成量提升。此外，经历过热浪的椎实螺在热浪结束后出现繁殖能力与营养盐排泄能力下降的现象，这表明存在具有生态学意义的延迟效应的可能性。本研究表明，胁迫因子对个体生物的即时与延迟效应，可能通过直接或间接途径影响多项生态系统功能。尤为重要的是，环境胁迫对个体消费者的延迟效应，可能因扰动后生态功能的下降而累积阻碍生态系统的恢复。将本研究结果与纳入更高生物复杂度层级响应的相关研究相结合，将进一步增强我们预测个体响应如何尺度上推至生态系统多功能性的能力。