Hakai Institute, Heriot Bay, BC V0P 1H0, Canada;
Biodiversity Research Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Proc Natl Acad Sci U S A. 2020 Nov 10;117(45):28160-28166. doi: 10.1073/pnas.2005255117. Epub 2020 Oct 26.
The global distribution of primary production and consumption by humans (fisheries) is well-documented, but we have no map linking the central ecological process of consumption within food webs to temperature and other ecological drivers. Using standardized assays that span 105° of latitude on four continents, we show that rates of bait consumption by generalist predators in shallow marine ecosystems are tightly linked to both temperature and the composition of consumer assemblages. Unexpectedly, rates of consumption peaked at midlatitudes (25 to 35°) in both Northern and Southern Hemispheres across both seagrass and unvegetated sediment habitats. This pattern contrasts with terrestrial systems, where biotic interactions reportedly weaken away from the equator, but it parallels an emerging pattern of a subtropical peak in marine biodiversity. The higher consumption at midlatitudes was closely related to the type of consumers present, which explained rates of consumption better than consumer density, biomass, species diversity, or habitat. Indeed, the apparent effect of temperature on consumption was mostly driven by temperature-associated turnover in consumer community composition. Our findings reinforce the key influence of climate warming on altered species composition and highlight its implications for the functioning of Earth's ecosystems.
人类(渔业)初级生产力和消费的全球分布已有详细记录,但我们没有将食物网中消费这一核心生态过程与温度和其他生态驱动因素联系起来的图谱。我们使用跨越四大洲 105°纬度的标准化测定方法,表明浅海生态系统中通用捕食者对诱饵的消耗率与温度和消费者组合的组成密切相关。出乎意料的是,在南北半球的海草草甸和无植被沉积物生境中,消费率都在中纬度(25 到 35°)达到峰值。这一模式与陆地系统形成鲜明对比,据报道,生物相互作用在远离赤道的地方减弱,但它与海洋生物多样性的亚热带峰值这一新兴模式相吻合。中纬度地区更高的消费率与存在的消费者类型密切相关,这比消费者密度、生物量、物种多样性或栖息地更能解释消费率。事实上,温度对消费的明显影响主要是由消费者群落组成随温度变化的更替驱动的。我们的研究结果强调了气候变暖对物种组成改变的关键影响,并突出了其对地球生态系统功能的影响。