Velocity-amplified microbial respiration rates in the lower Amazon River: Amazon River respiration
Velocity-amplified microbial respiration rates in the lower Amazon River: Amazon River respiration
复制标题
亚马逊河下游的速度放大微生物呼吸速率：亚马逊河呼吸
DOI：
10.1002/lol2.10062
复制
发表时间：
2018
影响因子：
7.8
通讯作者：
Richey, Jeffrey E.
中科院分区：
文献类型：
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作者：
Ward, Nicholas D.;Sawakuchi, Henrique O.;Neu, Vania;Less, Diani F. S.;Valerio, Aline M.;Cunha, Alan C.;Kampel, Milton;Bianchi, Thomas S.;Krusche, Alex V.;Richey, Jeffrey E.
在大型热带河流中，对呼吸速率的大多数测量都没有考虑河流水流条件对微生物活动的影响。我们开发了一套船载旋转孵化系统，用于测量不同转速下的O2下降，并将该系统部署在亚马逊河下游的四个水文时段。在0.22m S−1和0.66m S−1旋转孵化室中的平均呼吸速率分别是静止孵化室的1.4倍和2.4倍。平均而言，在0.22m S−1和0.66m S−1旋转的气室中的深度积分呼吸率分别占主干场地CO2放气率的% ± 22%和104% ± 36%。还进行了现场pCO2的连续测量，以及跨航道的河流流速剖面。下游河道流速与pCO2呈正相关(R2= 0.67~0.96)，整个潮汐周期内流速与pCO2呈正相关。
Most measurements of respiration rates in large tropical rivers do not account for the influence of river flow conditions on microbial activity. We developed a ship‐board spinning incubation system for measuring O2drawdown under different rotation velocities and deployed the system along the lower Amazon River during four hydrologic periods. Average respiration rates in incubation chambers rotated at 0.22 m s−1and 0.66 m s−1were 1.4 and 2.4 times higher than stationary chambers, respectively. On average, depth‐integrated respiration rates in chambers spun at 0.22 m s−1and 0.66 m s−1accounted for 64% ± 22% and 104% ± 36% of CO2outgassing rates, respectively, in mainstem sites. Continuous measurements of in situ pCO2were also made along with cross‐channel profiles of river velocity. A positive correlation between river velocity and pCO2was observed along the lower river (r2= 0.67–0.96) and throughout a tidal cycle.