Coastal and Marine Research Centre, Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, Queensland, Australia.
Ecol Lett. 2022 Dec;25(12):2611-2623. doi: 10.1111/ele.14120. Epub 2022 Oct 11.
Ecosystems remain under enormous pressure from multiple anthropogenic stressors. Manipulative experiments evaluating stressor interactions and impacts mostly apply stressors under static conditions without considering how variable stressor intensity (i.e. fluctuations) and synchronicity (i.e. timing of fluctuations) affect biological responses. We ask how variable stressor intensity and synchronicity, and interaction type, can influence how multiple stressors affect seagrass. At the highest intensities, fluctuating stressors applied asynchronously reduced seagrass biomass 36% more than for static stressors, yet no such difference occurred for photosynthetic capacity. Testing three separate hypotheses to predict underlying drivers of differences in biological responses highlighted alternative modes of action dependent on how stressors fluctuated over time. Given that environmental conditions are constantly changing, assessing static stressors may lead to inaccurate predictions of cumulative effects. Translating multiple stressor experiments to the real world, therefore, requires considering variability in stressor intensity and the synchronicity of fluctuations.
生态系统仍然承受着多种人为压力源的巨大压力。评估压力源相互作用和影响的操纵性实验主要在静态条件下施加压力源，而不考虑压力源强度（即波动）和同步性（即波动的时间）如何影响生物反应。我们想知道，可变的压力源强度和同步性以及相互作用类型如何影响多种压力源对海草的影响。在最高强度下，异步施加的波动压力源使海草生物量减少了 36%，而静态压力源则没有这种差异，但光合作用能力没有差异。通过测试三个单独的假设来预测生物反应差异的潜在驱动因素，突出了依赖于压力源随时间波动的不同作用模式。鉴于环境条件一直在变化，评估静态压力源可能会导致对累积效应的预测不准确。因此，将多压力源实验转化到现实世界中需要考虑压力源强度的可变性和波动的同步性。
