Dissolved organic matter (DOM) represents a mixture of organic molecules that vary due to different source materials and degree of processing. Characterizing how DOM composition evolves along the aquatic continuum can be difficult. Using a size‐exclusion chromatography technique (liquid chromatography‐organic carbon detection [LC‐OCD]), we assessed the variability in DOM composition from both surface and groundwaters across a number of Canadian ecozones (mean annual temperature spanning −10°C to +6°C). A wide range in DOM concentration was found from 0.2 to 120 mg C L⁻¹. Proportions of different size‐based groupings across ecozones were variable, yet similarities between specific waterbody types, regardless of location, suggest commonality in the processes dictating DOM composition. A principal component analysis identified 70% of the variation in LC‐OCD derived DOM compositions could be explained by the waterbody type. We find that DOM composition within a specific waterbody type is similar regardless of the differences in climate or surrounding vegetation where the sample originated from.

中文翻译：

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基于尺寸的淡水溶解有机物表征发现加拿大不同生态区的水体类型相似

溶解的有机物（DOM）代表有机分子的混合物，这些有机分子由于不同的原料和加工程度而有所不同。表征DOM成分沿水生连续体的演化可能很困难。使用尺寸排阻色谱技术（液相色谱-有机碳检测[LC-OCD]），我们评估了加拿大多个生态区的地表水和地下水中DOM组成的变异性（平均年温度范围为−10°C至+ 6°C）。发现DOM浓度范围从0.2到120 mg C L ^-1。整个生态区中基于大小的不同分组的比例是可变的，但是特定水体类型之间的相似性，无论其位置如何，都表明在决定DOM组成的过程中具有通用性。主成分分析确定了LC-OCD衍生的DOM成分变化的70％可以由水体类型来解释。我们发现特定水体类型内的DOM组成是相似的，而不管气候或样品所源自的周围植被的差异。