Department of Ecology and Evolutionary Biology, University of Arizona, Arizona, AZ 85721, USA.
The Santa Fe Institute, 1399 Hyde Park Rd, Santa Fe, NM, 87501, USA.
Nat Commun. 2020 Feb 4;11(1):699. doi: 10.1038/s41467-020-14369-y.
A prominent signal of the Anthropocene is the extinction and population reduction of the megabiota-the largest animals and plants on the planet. However, we lack a predictive framework for the sensitivity of megabiota during times of rapid global change and how they impact the functioning of ecosystems and the biosphere. Here, we extend metabolic scaling theory and use global simulation models to demonstrate that (i) megabiota are more prone to extinction due to human land use, hunting, and climate change; (ii) loss of megabiota has a negative impact on ecosystem metabolism and functioning; and (iii) their reduction has and will continue to significantly decrease biosphere functioning. Global simulations show that continued loss of large animals alone could lead to a 44%, 18% and 92% reduction in terrestrial heterotrophic biomass, metabolism, and fertility respectively. Our findings suggest that policies that emphasize the promotion of large trees and animals will have disproportionate impact on biodiversity, ecosystem processes, and climate mitigation.
人类世的一个显著标志是巨型生物群（地球上最大的动植物）的灭绝和数量减少。然而，我们缺乏一个预测框架来了解巨型生物群在快速全球变化时期的敏感性，以及它们如何影响生态系统和生物圈的功能。在这里，我们扩展了代谢缩放理论，并使用全球模拟模型来证明：(i) 巨型生物群由于人类土地利用、狩猎和气候变化更容易灭绝；(ii) 巨型生物群的丧失对生态系统代谢和功能有负面影响；(iii) 它们的减少已经并将继续显著降低生物圈的功能。全球模拟表明，仅大型动物的持续丧失可能分别导致陆地异养生物量、代谢和肥力减少 44%、18%和 92%。我们的研究结果表明，强调促进大型树木和动物的政策将对生物多样性、生态系统过程和减缓气候变化产生不成比例的影响。
