PDF(Pubmed)
Abstract：
Heterotrophic Bacteria and Archaea (prokaryotes) are a major component of marine food webs and global biogeochemical cycles. Yet, there is limited understanding about how prokaryotes vary across global environmental gradients, and how their global abundance and metabolic activity (production and respiration) may be affected by climate change. Using global datasets of prokaryotic abundance, cell carbon and metabolic activity we reveal that mean prokaryotic biomass varies by just under 3-fold across the global surface ocean, while total prokaryotic metabolic activity increases by more than one order of magnitude from polar to tropical coastal and upwelling regions. Under climate change, global prokaryotic biomass in surface waters is projected to decline ~1.5% per °C of warming, while prokaryotic respiration will increase ~3.5% ( ~ 0.85 Pg C yr-1). The rate of prokaryotic biomass decline is one-third that of zooplankton and fish, while the rate of increase in prokaryotic respiration is double. This suggests that future, warmer oceans could be increasingly dominated by prokaryotes, diverting a growing proportion of primary production into microbial food webs and away from higher trophic levels as well as reducing the capacity of the deep ocean to sequester carbon, all else being equal.
摘要：
异养细菌和古细菌（原核生物）是海洋食物网和全球生物地球化学循环的主要组成部分。然而，对原核生物在全球环境梯度中的变化了解有限，以及它们的全球丰度和代谢活动（生产和呼吸）如何受到气候变化的影响。利用原核生物丰度的全球数据集，细胞碳和代谢活性我们揭示了平均原核生物生物量在全球海洋表面变化不到3倍，从极地到热带沿海和上升流地区，原核生物的总代谢活性增加了一个以上的数量级。在气候变化下,全球地表水中的原核生物生物量预计每摄氏度变暖将下降约1.5%，而原核呼吸将增加~3.5%(~0.85PgCyr-1)。原核生物生物量下降的速度是浮游动物和鱼类的三分之一，而原核呼吸的增加速率是两倍。这表明未来，温暖的海洋可能越来越多地由原核生物主导，将越来越多的初级生产转移到微生物食物网中，远离较高的营养水平，并降低深海固碳的能力，其他一切都平等。
