▲ 作者:M. Bressac, E. C. Laurenceau-Cornec et al.
▲ 链接:
https://www.nature.com/articles/s41586-024-07850-x
▲ 摘要:
在此,我们展示了C-RESPIRE的原位实验结果。C-RESPIRE是一种部署在多个中层深度的双粒子拦截器和培养箱,用于测量微生物介导的颗粒有机碳(POC)通量衰减。
我们发现,在6个不同的海洋体系中,即POC通量的30倍范围内,颗粒附着微生物的降解为通量衰减的7%—29%,这意味着浮游动物在通量衰减中发挥了更大的影响作用。微生物再矿化,标准化到POC通量,在不同的地点和深度范围20倍,在高POC通量下速率最低。
高达三倍变化的垂直趋势与低纬度地区强烈的温度梯度有关。与之相反,在中高纬度地区,温度的影响较小,而垂直趋势可能由颗粒生物化学、破碎化和微生物生态生理共同决定。马丁曲线的解构揭示了驱动微生物介导的POC通量衰减的基本机制。
▲ Abstract:
Here we present in situ experimental findings from C-RESPIRE, a dual particle interceptor and incubator deployed at multiple mesopelagic depths, measuring microbially mediated POC flux attenuation. We find that across six contrasting oceanic regimes, representing a 30-fold range in POC flux, degradation by particle-attached microbes comprised 7–29 per cent of flux attenuation, implying a more influential role for zooplankton in flux attenuation. Microbial remineralization, normalized to POC flux, ranged by 20-fold across sites and depths, with the lowest rates at high POC fluxes. Vertical trends, of up to threefold changes, were linked to strong temperature gradients at low-latitude sites. In contrast, temperature played a lesser role at mid- and high-latitude sites, where vertical trends may be set jointly by particle biochemistry, fragmentation and microbial ecophysiology. This deconstruction of the Martin curve reveals the underpinning mechanisms that drive microbially mediated POC flux attenuation across oceanic provinces.