Metabolic theory predicts whole-ecosystem properties
Metabolic theory predicts whole-ecosystem properties
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DOI：
10.1073/pnas.1423502112
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发表时间：
2015-01
期刊：
影响因子：
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通讯作者：
J. Schramski;A. Dell;J. Grady;R. Sibly;James H. Brown
中科院分区：
文献类型：
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作者：
J. Schramski;A. Dell;J. Grady;R. Sibly;James H. Brown
意义提出了一种理论，它显示了个体生物体的新陈代谢如何控制碳在生态系统中的流动。该理论综合了自上而下，生态系统水平和自下而上，生物体水平的方法来研究生态能量学和物质循环。该理论预测碳分子的停留时间与整个生态系统生物量与初级生产力的比率之间存在非常简单的直线关系。这一预测和其他预测的总贯流和再循环的支持数值模型和数据从真实的生态系统。该理论提供了一种强有力的方法来理解生物体在生态系统过程中的作用，从局部栖息地到生物圈。这种理解对于应对人为造成的气候、土地利用和生物多样性变化的影响非常重要。了解生物个体对生态系统内物质循环和能量通量的影响，对于预测人为变化对气候、土地利用和生物多样性的影响至关重要。在这里，我们提出了一个理论，整合代谢（基于有机体的自下而上）和系统（基于生态系统的自上而下）的方法来表征个人的新陈代谢如何影响生态系统中的物质和能量的流动和储存。该理论预测了碳分子的平均停留时间，总系统通流（TST）和回收量如何随生物体的大小和温度以及营养组织而变化。我们评估的理论比较理论预测与数值模型的输出，旨在模拟不同的生态系统类型和经验数据为真实的生态系统。虽然停留时间在不同的生态系统不同的数量级-从数周在温暖的远洋海洋与微小的浮游植物生产者到数百年在寒冷的森林与大型树木生产者预测，所有的生态系统下降沿着一条线：停留时间线性增加斜率= 1.0与整个生态系统的生物量的比率，初级生产力（B/P）。TST主要受初级生产力和能量从微生物分解者转移到动物消费者的再循环的影响。该理论为估算陆地、海洋和淡水生态系统中能量、碳和其他物质的通量和储存量提供了坚实的基础，也为量化从局部生态系统到生物圈的不同类型生物和环境的作用提供了坚实的基础。
Significance A theory is presented which shows how the metabolism of individual organisms controls the flow of carbon through ecosystems. The theory synthesizes top-down, ecosystem-level and bottom-up, organism-level approaches to ecological energetics and material cycles. The theory predicts a very simple straight-line relationship between residence time of carbon molecules and the ratio of whole-ecosystem biomass to primary productivity. This and additional predictions for total throughfow and recycling are supported by numerical models and data from real ecosystems. The theory provides a powerful way to understand the roles of organisms in ecosystem processes at scales from local habitats to the biosphere. Such an understanding is important for addressing the impacts of human-caused changes in climate, land use, and biodiversity. Understanding the effects of individual organisms on material cycles and energy fluxes within ecosystems is central to predicting the impacts of human-caused changes on climate, land use, and biodiversity. Here we present a theory that integrates metabolic (organism-based bottom-up) and systems (ecosystem-based top-down) approaches to characterize how the metabolism of individuals affects the flows and stores of materials and energy in ecosystems. The theory predicts how the average residence time of carbon molecules, total system throughflow (TST), and amount of recycling vary with the body size and temperature of the organisms and with trophic organization. We evaluate the theory by comparing theoretical predictions with outputs of numerical models designed to simulate diverse ecosystem types and with empirical data for real ecosystems. Although residence times within different ecosystems vary by orders of magnitude—from weeks in warm pelagic oceans with minute phytoplankton producers to centuries in cold forests with large tree producers—as predicted, all ecosystems fall along a single line: residence time increases linearly with slope = 1.0 with the ratio of whole-ecosystem biomass to primary productivity (B/P). TST was affected predominantly by primary productivity and recycling by the transfer of energy from microbial decomposers to animal consumers. The theory provides a robust basis for estimating the flux and storage of energy, carbon, and other materials in terrestrial, marine, and freshwater ecosystems and for quantifying the roles of different kinds of organisms and environments at scales from local ecosystems to the biosphere.