Data from a photochemical and biological degradation experiment carried out on dissolved organic matter from thermokarstic ponds representing a gradient of erosion and terrestrial inputs, Bylot Island, Nunavut, Canada.

These data originate from a dissolved organic matter (DOM) degradation experiment carried out at Bylot Island (Qarlikturvik Valley, 73°09’N, 79°58’W), in the eastern Canadian Arctic. The site is a thick peaty terrain underlain with continuous syngenetic permafrost and structured in ice-wedge polygons. It is covered with thousands of shallow ponds forming a typical polygonal tundra landscape. Water was sampled from 6 thermokarst ponds and a 14-day incubation was carried out between 3rd and 16th July 2017 at the water surface. Water was filtered and distributed into bottles exposed to sunlight or covered from it to generate treatments and evaluate the efficiency of DOM photodegradation and biodegradation. Dissolved organic carbon, along with optical variables characterizing the chromophoric fraction of DOM (a320, SUVA254, fluorescent PARAFAC components…) and microbial abundance, were measured at the beginning and end of the incubation. The originality of the study is that ponds were selected to obtain a gradient of terrestrial inputs from surrounding eroding permafrost soil, including two erosive ice-wedge trough ponds, two stable ice-wedge trough ponds and two coalescent polygon ponds.

本数据集源于在加拿大北极东部比洛特岛（卡拉基图里克山谷，北纬73°09'，西经79°58'）进行的溶解有机质（DOM）降解实验。该地区为厚实的泥炭地形，其下为连续的同期冻土，并形成冰楔多边形结构。地表覆盖着成千上万的浅水池塘，构成典型的多边形苔原景观。2017年7月3日至16日，在水面处对6个热喀斯特池塘进行了水样采集，并进行了为期14天的培养。水样经过过滤后，分别置于暴露于阳光和避光的环境中，以生成处理样本并评估DOM光降解和生物降解的效率。在培养开始和结束时，对溶解有机碳、表征DOM着色组分的光学变量（如a320、SUVA254、荧光PARAFAC组分）以及微生物丰度进行了测量。本研究的创新之处在于，通过选择池塘，以获取来自周围侵蚀冻土土壤的陆地输入梯度，包括两个侵蚀性冰楔槽池塘、两个稳定冰楔槽池塘和两个融合多边形池塘。