Spatial and temporal variability of biogenic isoprene emissions from a temperate estuary
Spatial and temporal variability of biogenic isoprene emissions from a temperate estuary
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DOI：
10.1029/2011gb004210
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发表时间：
2012-05-08
影响因子：
5.2
通讯作者：
McGenity, T. J.
中科院分区：
文献类型：
--
作者：
Exton, D. A.;Suggett, D. J.;McGenity, T. J.
异戊二烯对大气的影响及其对排放生物的生态生理益处很重要；然而，与陆地系统相比，海洋系统的异戊二烯排放研究仍然很少。这项研究首次调查了温带河口异戊二烯生产的驱动因素，以及这种生产在使生物体能够耐受固有的广泛环境条件方面可能发挥的作用。在一年多的时间里，每六周从英国科尔纳河口沿岸的四个地点采集潮间带沉积物岩心以及涨潮和低潮水样。水中异戊二烯浓度在低潮时明显高于涨潮时，并在河口附近呈下降趋势；产沙量无空间变异性。异戊二烯浓度随着光照的增加而增加，随着潮汐高度的增加而减少；夜间生产量比白天生产量低79%。季节异戊二烯产量和水分浓度在最温暖的月份最高，产量与光照(r(2)=0.800)和温度(r(2)=0.752)密切相关。潮间带微型底栖植物群落是异戊二烯的主要来源，潮汐作用是异戊二烯进入水体的集中因素。利用这些数据，我们估算出该河口的年生产量为681亩/年。这一数值位于其他海洋估算值的上端，突出了河口作为异戊二烯来源的潜在重要作用。本文确定的环境过程对河口异戊二烯生产的控制进一步表明，这种排放可能会因未来的环境变化而改变。
Isoprene is important for its atmospheric impacts and the ecophysiological benefits it affords to emitting organisms; however, isoprene emissions from marine systems remain vastly understudied compared to terrestrial systems. This study investigates for the first time drivers of isoprene production in a temperate estuary, and the role this production may play in enabling organisms to tolerate the inherently wide range of environmental conditions. Intertidal sediment cores as well as high and low tide water samples were collected from four sites along the Colne Estuary, UK, every six weeks over a year. Isoprene concentrations in the water were significantly higher at low than high tide, and decreased toward the mouth of the estuary; sediment production showed no spatial variability. Diel isoprene concentration increased with light availability and decreased with tidal height; nighttime production was 79% lower than daytime production. Seasonal isoprene production and water concentrations were highest for the warmest months, with production strongly correlated with light (r(2) = 0.800) and temperature (r(2) = 0.752). Intertidal microphytobenthic communities were found to be the primary source of isoprene, with tidal action acting as a concentrating factor for isoprene entering the water column. Using these data we estimated an annual production rate for this estuary of 681 mu mol m(-2) y(-1). This value falls at the upper end of other marine estimates and highlights the potentially significant role of estuaries as isoprene sources. The control of estuarine isoprene production by environmental processes identified here further suggests that such emissions may be altered by future environmental change.