Temporal dynamics of dissolved organic matter (DOM) in mountain lakes: the role of catchment characteristics
Temporal dynamics of dissolved organic matter (DOM) in mountain lakes: the role of catchment characteristics
复制标题
高山湖泊溶解有机物 (DOM) 的时间动态：流域特征的作用
DOI：
10.1139/cjfas-2020-0421
复制
发表时间：
2022
影响因子：
2.4
通讯作者：
Hayashi, Masaki
中科院分区：
文献类型：
--
作者：
Olson, Mark H.;Fischer, Janet M.;Hayashi, Masaki
气候变化正在通过增加植被覆盖率和改变气象条件来影响山区生态系统。这些变化可能会影响从周围集水区输入湖泊的溶解有机物(DOM)的时间和数量。我们利用原位光学传感器测量了五个不同集水特征的湖泊在非冰季的DOM荧光(FDOM)，研究了DOM的时间动态。我们还测量了湖泊水位的变化，并汇编了附近气象站的每日气象数据。在季节性时间尺度上，fDOM动态发生在两个阶段。FDOM在第一阶段下降，一直持续到7月下旬至8月中旬，与春季融雪后湖泊水位下降相对应。这种下降在有更多植被集水区的湖泊中更为明显。在较短的时间尺度上，fDOM随着降水事件的发生而增加，具有0-1天的滞后。在有植被集水区的湖泊中，fDOM的增长率在湖平面变化的百分之一处更大。随着气候变化增加植被覆盖率，DOM在日常和季节性时间尺度上可能会变得更加动态，并影响山区湖泊的水透明度和生产力。
Climate change is affecting mountain ecosystems by increasing vegetation coverage and altering meteorological conditions. These changes are likely to impact the timing and magnitude of dissolved organic matter (DOM) inputs to lakes from the surrounding catchment. We examined temporal dynamics of DOM using in situ optical sensors that measured DOM fluorescence (fDOM) through the ice-free season in five lakes with differing catchment characteristics. We also measured changes in lake level and compiled daily meteorological data from nearby weather stations. At a seasonal time scale, fDOM dynamics occurred in two phases. fDOM declined in the first phase, which lasted until late July – mid-August, and corresponded to a decline in lake level following spring snowmelt. This decline was more pronounced in lakes with more vegetated catchments. At a shorter time scale, fDOM increased following precipitation events with a 0- to 1-day lag. Rates of fDOM increase per centmetre change in lake level were greater in lakes with vegetated catchments. As climate change increases vegetation coverage, DOM will likely become more dynamic at daily and seasonal time scales and impact water transparency and productivity of mountain lakes.