Concentrations of trace elements measured in lichens and soils at Lhù'ààn Mân' (Kluane Lake, Yukon Territory, Canada) in August 2021

We observed increased trace element concentrations in lichens and soils at sites closer to the dust source. Vegetation was more impacted by dust deposition, as well as the 0-2 cm soil layer compared to the 2-10 soil layer. The parameters measured were nickel (Ni) (mg/kg), copper (Cu) (mg/kg), arsenic (As) (mg/kg), cadmium (Cd) (mg/kg), lead (Pb) (mg/kg), total carbon (C) (%), total nitrogen (N) (%), total phosphorus (P) (mg/kg), CN ratio and pH in lichens and soils, manganese (Mn) (mg/kg), magnesium (Mg) (mg/kg), potassium (K) (mg/kg), aluminum (Al) (mg/kg), calcium (Ca) (mg/kg), iron (Fe) (mg/kg), sodium (Na) (mg/kg) in soils, tree, shrub, herb, moss and lichen cover (%). Terricolous lichen Peltigera canina was sampled with a stainless-steel knife and scissors in three replicas at 53 sites within 10 km of the delta, and 4 control sites at 11 and 30 km. Sampling sites were located near the roads for accessibility reasons, but the sampling was done at least 100 m from the road to lessen the influence of the road itself. Two layers were sampled, one at 0-2 cm and the other one at 2-10 cm in three replicas at each site with a stainless trowel. Lichen samples were digested in 2 mL of HNO3, and soil samples in 4 mL of HNO3 and 1 mL of HCl. Trace elements (Ni, Cu, As, Cd, Pb) were determined in lichens and soils, and minor elements (Al, Ca, Fe, K, Mg, Mn, and Na) in soils by Inductively coupled plasma mass spectrometry (ICP-MS; PerkinElmer NexION 300x, PerkinElmer Syngistix). Total carbon and nitrogen concentrations were analyzed by CHNO-S elemental analysis, Fisons - EA-1108 CHNS-O Element Analyzer. Total P content was analyzed using Shimadzu UV spectrophotometry. The pH was analyzed with a pH meter Fisher Accumet pH Meter AB 150. The percent cover of vegetation layer (tree, shrub, herb, moss, and lichen) was characterized within a 20-meter radius around the central point of each sampling site. We followed the inventory method recommended by the Field Manual for Describing Terrestrial Ecosystems (Erwin, 2010), which is used by the territory (Environment Yukon, 2016, 2017). The data was collected in the field in August 2021 and the analyses were performed between September 2021 and February 2022. The temporal coverage is yearly. The data collection was done at Lhù'ààn Mân' (Kluane Lake), Yukon Territory, Canada. The geographical coverage is regional. The dataset covers 33 km with 57 sites. […]

本研究观测到，距离粉尘源越近的样地，其地衣与土壤中的微量元素浓度越高。相较于2-10 cm土层，植被以及0-2 cm土层受粉尘沉降的影响更为显著。
本次测定的参数包括：地衣与土壤中的镍（nickel, Ni）（mg/kg）、铜（copper, Cu）（mg/kg）、砷（arsenic, As）（mg/kg）、镉（cadmium, Cd）（mg/kg）、铅（lead, Pb）（mg/kg）、总碳（total carbon, C）（%）、总氮（total nitrogen, N）（%）、总磷（total phosphorus, P）（mg/kg）、碳氮比（CN ratio）与pH值；土壤中的锰（manganese, Mn）（mg/kg）、镁（magnesium, Mg）（mg/kg）、钾（potassium, K）（mg/kg）、铝（aluminum, Al）（mg/kg）、钙（calcium, Ca）（mg/kg）、铁（iron, Fe）（mg/kg）、钠（sodium, Na）（mg/kg）；以及乔木、灌木、草本、苔藓与地衣的盖度（%）。
研究人员使用不锈钢刀具与剪刀，在三角洲10 km范围内的53个样地，以及11 km、30 km处的4个对照样地，采集了地表生地衣狗鳞叶衣（Peltigera canina），每个样地设置3个重复样本。为兼顾野外可达性，采样点设于道路附近，但所有采样操作均距离道路至少100 m，以降低道路本身对采样结果的干扰。在每个样地，研究人员使用不锈钢抹刀采集两层土壤样品：0-2 cm土层与2-10 cm土层，同样设置3个重复样本。
地衣样品采用2 mL硝酸（HNO₃）进行消解，土壤样品则采用4 mL硝酸与1 mL盐酸（HCl）进行消解。
采用电感耦合等离子体质谱法（Inductively coupled plasma mass spectrometry, ICP-MS；PerkinElmer NexION 300x，PerkinElmer Syngistix）测定地衣与土壤中的微量元素（Ni、Cu、As、Cd、Pb），以及土壤中的次要元素（Al、Ca、Fe、K、Mg、Mn、Na）；总碳与总氮浓度采用CHNO-S元素分析法测定，使用Fisons EA-1108 CHNS-O元素分析仪；总磷含量采用岛津（Shimadzu）紫外分光光度法测定；pH值采用Fisher Accumet AB 150 pH计进行测定。
在每个采样点中心点周边20 m半径范围内，研究人员对植被层（乔木、灌木、草本、苔藓与地衣）的盖度进行了调查。本研究遵循《陆地生态系统描述野外手册》（Erwin, 2010）推荐的调查方法，该方法亦被育空地区环境署（Environment Yukon, 2016, 2017）采用。
本研究的野外数据采集于2021年8月完成，实验室分析工作于2021年9月至2022年2月期间进行，时间覆盖周期为年度。数据采集工作开展于加拿大育空地区的Lhù'ààn Mân'（克卢恩湖，Kluane Lake），样地地理覆盖范围为区域尺度。本数据集覆盖跨度33 km，共包含57个采样点。……