Intra- and inter-annual variability in metabolism in an oligotrophic lake
Intra- and inter-annual variability in metabolism in an oligotrophic lake
复制标题
寡营养湖新陈代谢的年内和年际变化
DOI：
10.1007/s00027-016-0499-7
复制
发表时间：
2016
期刊：
影响因子：
2.4
通讯作者：
K. Weathers
中科院分区：
文献类型：
--
作者：
D. C. Richardson;C. Carey;D. Bruesewitz;K. Weathers
湖泊是其所在景观变化的哨兵。湖泊功能的变化反映在整个系统的新陈代谢，它整合了跨空间和时间尺度的生态系统过程。最近在高频开放水域代谢建模技术的改进，使估计的总初级生产力（GPP），呼吸（R），和净生态系统生产力（NEP）在高时间分辨率。然而，很少有研究研究在日常到多年的时间尺度上的代谢率，特别是在贫营养生态系统。在这里，我们修改了代谢建模技术，以揭示大量的年内和年际变化的代谢率在苏纳皮湖，温带，贫营养湖在新罕布什尔州，美国。每年GPP和R增加，每年夏天，平行增加沿岸的，但不是远洋，总磷浓度。风暴暂时解除了GPP和R的耦合，导致GPP的下降幅度大于R。日速率的GPP和R呈正相关，在温暖的日子，有稳定的水柱，和代谢模型拟合最好的温暖，阳光明媚的日子，表明湖泊物理学的重要性时，评估代谢率。这些代谢数据跨越了一系列的时间尺度，共同表明，苏纳皮湖可能正在向中营养方向发展。我们认为，功能，综合指标，如代谢率，是有用的指标和生态系统变化的哨兵。我们还强调了使用高频测量来阐明代谢率的年内和年际变化的驱动因素和后果的挑战和机遇，特别是在贫营养湖泊中。
Lakes are sentinels of change in the landscapes in which they are located. Changes in lake function are reflected in whole-system metabolism, which integrates ecosystem processes across spatial and temporal scales. Recent improvements in high-frequency open-water metabolism modeling techniques have enabled estimation of rates of gross primary production (GPP), respiration (R), and net ecosystem production (NEP) at high temporal resolution. However, few studies have examined metabolic rates over daily to multi-year temporal scales, especially in oligotrophic ecosystems. Here, we modified a metabolism modeling technique to reveal substantial intra- and inter-annual variability in metabolic rates in Lake Sunapee, a temperate, oligotrophic lake in New Hampshire, USA. Annual GPP and R increased each summer, paralleling increases in littoral, but not pelagic, total phosphorus concentrations. Storms temporarily decoupled GPP and R, resulting in greater decreases in GPP than R. Daily rates of GPP and R were positively correlated on warm days that had stable water columns, and metabolism model fits were best on warm, sunny days, indicating the importance of lake physics when evaluating metabolic rates. These metabolism data span a range of temporal scales and together suggest that Lake Sunapee may be moving toward mesotrophy. We suggest that functional, integrative metrics, such as metabolic rates, are useful indicators and sentinels of ecosystem change. We also highlight the challenges and opportunities of using high-frequency measurements to elucidate the drivers and consequences of intra- and inter-annual variability in metabolic rates, especially in oligotrophic lakes.