SPRUCE S1 Bog Porewater, Groundwater, and Stream Chemistry Data: 2011-2013

This data set reports the chemistry of S1 bog porewater, outlet stream water, and groundwater from upland wells from 2011 through 2013. The experimental work is to be conducted in a Picea mariana [black spruce] - Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). These data provide information for studies of the biogeochemical status of the bog and surrounding groundwater aquifer. Porewater samples were collected from one nest of 6 piezometers installed in a hollow in the south end of the S1 bog to characterize solute chemistry depth profiles. Peat porewater was collected from piezometers that opened at 0, 0.3, 0.5, 1, 2, and 3 m depths below hollow surfaces. Samples were collected weekly (2011) or monthly (2012 & 2013) when the samplers were not frozen (typically June - November). Stream water was sampled weekly (2011-2013) from the outlet of the S1 bog (located on the southern edge of the bog). Four groundwater wells located in the uplands of the S1 watershed were sampled monthly in 2013. Bog water level data are also reported for the S1 bog. Water samples were analyzed for pH, specific conductivity, nutrient concentrations (ammonium, nitrate, soluble reactive phosphorus, total nitrogen, total phosphorus), cation concentrations (calcium, potassium, magnesium, sodium, aluminum, iron, manganese, silicon, strontium), anion concentrations (chloride, sulfate), and total organic carbon concentrations. Please refer to the provided documentation (SPRUCE_S1_bog_porewater_groundwater_and_stream_chemistry_data_2011_2013_*.pdf) for maps, photos, and measurement details.

本数据集记录了2011至2013年间，美国明尼苏达州北部格兰德港（Grand Rapids）以北40公里处的美国农业部（USDA）林务局马塞尔实验林（Marcell Experimental Forest, MEF）内S1泥炭沼泽的孔隙水、出口溪流水以及流域高地井地下水的化学特征。该研究场地为黑云杉（Picea mariana）-泥炭藓属（Sphagnum spp.）组成的沼泽森林。本数据集可为泥炭沼泽及其周边地下水含水层的生物地球化学状态研究提供核心基础数据。
孔隙水样品采集自S1泥炭沼泽南端洼地内布设的1组6支测压管（piezometer），用于解析溶质化学的垂向分布特征。本次采集的泥炭孔隙水来自埋设深度分别为洼地表面下0、0.3、0.5、1、2及3米的测压管。样品采集频率为2011年每周1次，2012年与2013年每月1次，采集时段为测压管未冻结的时期（通常为6月至11月）。
2011至2013年间，研究团队每周对位于S1泥炭沼泽南缘的沼泽出口处的溪流水进行采样。2013年，研究团队每月对S1流域高地内的4口地下水井进行采样。本数据集同时包含S1泥炭沼泽的水位监测数据。
所有水样的分析指标包括pH值、比电导率、营养盐浓度（铵态氮、硝态氮、可溶性活性磷、总氮、总磷）、阳离子浓度（钙、钾、镁、钠、铝、铁、锰、硅、锶）、阴离子浓度（氯化物、硫酸盐）以及总有机碳浓度。如需获取点位地图、实拍照片及实验细节，请参阅配套文档（SPRUCE_S1_bog_porewater_groundwater_and_stream_chemistry_data_2011_2013_*.pdf）。