Changes in metabolic rates under fluctuating salinity regimes for two subtidal estuarine habitats
Changes in metabolic rates under fluctuating salinity regimes for two subtidal estuarine habitats
复制标题
两个潮下河口生境盐度波动情况下代谢率的变化
DOI：
10.2307/1352933
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
C. Oviatt
中科院分区：
文献类型：
--
作者：
C. Farris;C. Oviatt
个别栖息地的代谢率可以显着不同的贡献河口总系统生产力。不断变化的环境条件（例如潮汐交换造成的环境条件）经常会改变这些速率。在努力量化这些速率响应，代谢率测定在不同盐度的大型藻类和沉积物栖息地。代表这两种生境的微宇宙在三个盐度范围（高：25至31‰;中等：12至18‰;和低：0至4‰）下孵育，并估计生产和呼吸速率。这两种生境的生产率成正比的孵化中的水的盐度，与最低的代谢率与最低的盐度。在高、中、低盐度处理下，大型藻类栖息地的平均净生产率分别为879 mg O2 m-2 h-1、609 mg O2 m-2 h-1和451 mg O2 m-2 h-1，暗呼吸率分别为-401 mg O2 m-2 h-1、-341 mg O2 m-2 h-1和-333 mg O2 m-2 h-1。在高、中和低盐度处理下，平均沉积物生境净生产率分别为60 mg O2 m−2 h−1、13 mg O2 m − 2 h−1和10 mg O2 m−2 h−1，呼吸率分别为−114 mg O2 m−2 h−1、−55 mg O2 m−2 h−1和−31 mg O2 m−2 h−1。大型藻类栖息地对系统代谢的较大贡献可以解释一些河口水体氧含量的日变化。大型藻类的生产率解释了白天水柱氧含量增加的83%，大型藻类的呼吸率解释了夜间氧含量下降的65%。大型藻类代谢对系统的贡献甚至可以受到水柱盐度的短期变化的影响。在每小时的时间尺度上改变盐度水平的环境过程可能会缓和大型藻类代谢对氧水平的影响。
The metabolic rate of individual habitats can differ significantly in their contribution to the total system productivity of estuaries. Changing environmental conditions such as those created by tidal exchange can frequently alter these rates. In an effort to quantify these rate responses, metabolic rates were measured for macroalgal and sediment habitats at different salinities. Microcosms representing the two habitats were incubated at three salinity ranges (high: 25 to 31‰; moderate: 12 to 18‰; and low: 0 to 4‰) and production and respiration rates were estimated. The production rates for both habitats were proportional to the salinity of the water in the incubation, with the lowest metabolic rates associated with the lowest salinity. Average macroalgal habitat net production rates were 879 mg O2 m−2 h−1, 609 mg O2 m−2 h−1, and 451 mg O2 m−2 h−1 at high, moderate, and low salinity treatments, respectively, and the dark respiration rates were −401 mg O2 m−2 h−1, −341 mg O2 m−2 h−1, and −333 mg O2 m−2 h−1. Average sediment habitat net production rates were 60 mg O2 m−2 h−1, 13 mg O2 m−2 h−1 and 10 mg O2 m−2 h−1 and the respiration rates were −114 mg O2 m−2 h−1, −55 mg O2 m−2 h−1, and −31 mg O2 m−2 h−1 at high, moderate, and low salinity treatments. The larger contribution of macroalgal habitats to system metabolism may account for observed diurnal changes in water column oxygen levels in some estuaries. Macroalgal production rates explained 83% of the increase in water column oxygen levels during daylight hours and macroalgal respiration rates explained 65% of the decline in oxygen levels during the night. The contribution of macroalgal metabolism to the system can be influenced by even short-term changes in water column salinity. Environmental processes that alter salinity levels on hourly time scales may moderate the effect of macroalgal metabolism on oxygen levels.