Landscape Influence on the Browning of a Lake Watershed in the Adirondack Region of New York, USA
Landscape Influence on the Browning of a Lake Watershed in the Adirondack Region of New York, USA
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DOI：
10.3390/soilsystems4030050
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发表时间：
2020-08
期刊：
影响因子：
3.5
通讯作者：
Nicholas A. LoRusso;M. Mchale;P. McHale;M. Montesdeoca;Teng Zeng;Charles T. Driscoll
中科院分区：
文献类型：
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作者：
Nicholas A. LoRusso;M. Mchale;P. McHale;M. Montesdeoca;Teng Zeng;Charles T. Driscoll
美国东北部流域从长期酸化中恢复的特征是溶解有机物（DOM）流入地表沃茨的增加。碳量的增加和向芳香和“有色”有机物的转移通过改变热分层、营养循环和食物网动态对下游湖泊产生了影响。在这里，我们使用荧光光谱法与平行因子分析（PARAFAC）模型的主要碳质量分数和它们的季节性变化内表面沃茨沿着景观位置杨梅湖流域在美国纽约州的阿迪朗达克地区。所有的DOM组成部分都是陆地的起源，但它们的相对分数在整个流域变化。在源头流的DOM中含有高比例的柠檬酸盐（~43%）和微生物再加工的腐殖类OM（~33%），来自高地森林土壤。湖泊入口上方的湿地贡献了更高比例的高分子量植物样有机物（约30%），增加了湖泊入口处的溶解有机碳（DOC）浓度（492.5 mg L−1）。在湖泊出口，这些陆地部分显着减少，在夏季导致随后的增加，可能通过增加微生物代谢和光解的再加工OM。本研究与先前在杨梅湖的研究之间的特定紫外吸收率的比较表明，排放高地溪流（3.1 L·mg C−1 m−1）和湿地（4.1 L·mg C−1 m−1）的OM现在更芳香，因此比十年前的条件更具色彩。这些研究结果提供了深入了解流域从酸化中恢复对下游水质的新作用。
Watershed recovery from long-term acidification in the northeastern U.S. has been characterized by an increase in the influx of dissolved organic matter (DOM) into surface waters. Increases in carbon quantity and shifts to more aromatic and “colored” OM has impacted downstream lakes by altering thermal stratification, nutrient cycling and food web dynamics. Here, we used fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) to model predominant carbon quality fractions and their seasonal changes within surface waters along landscape positions of Arbutus Lake watershed in the Adirondack region of NY, USA. All DOM components were terrestrial in origin, however their relative fractions varied throughout the watershed. DOM in headwater streams contained high fractions of recalcitrant (~43%) and microbial reprocessed humic-like OM (~33%), sourced from upland forest soils. Wetlands above the lake inlet contributed higher fractions of high molecular weight, plant-like organic matter (~30%), increasing dissolved organic carbon (DOC) concentrations observed at the lake inlet (492.5 mg L−1). At the lake outlet, these terrestrial fractions decreased significantly during summer months leading to a subsequent increase in reprocessed OM likely through increased microbial metabolism and photolysis. Comparisons of specific ultraviolet absorbance between this study and previous studies at Arbutus Lake show that OM draining upland streams (3.1 L·mg C−1 m−1) and wetland (4.1 L·mg C−1 m−1) is now more aromatic and thus more highly colored than conditions a decade ago. These findings provide insight into the emerging role that watersheds recovering from acidification play on downstream water quality.