Dataset for Factors Regulating Lake Periphyton Biomass and Nutrient Limitation Status Across Large Trophic Gradient

This data set contains results of a study on the response of Great Lakes periphyton to additions of nutrients. Nutrient Diffusing Substrata (NDS) with control, +nitrogen, +phosphorus, and +nitrogen and phosphorus treatments were deployed at 28 sites along the coast of Lake Superior, northern Lake Michigan, and Green Bay. Control NDS cups contained just 2% agar by weight while +nitrogen, +phosphorus, and +nitrogen and phosphorus treatments contained the agar and 0.5 M NH4Cl, KH2PO4, or both, respectively. Experiments were deployed between July 11-31, 2017 and retrieved 28-29 days later between August 8-28, 2017. Periphyton biomass as chlorophyll-a and ash free dry weight (AFDW) from NDS treatments is contained in the file “NDS_Chl_AFDW.csv”. Site locations and environmental parameters (water column nutrient concentrations, Kd, and chlorophyll) are contained in the file “SITES_PARAMETERS”.

这个数据集包含五大湖附生植物（periphyton）对营养添加响应的研究结果。研究人员在苏必利尔湖沿岸、密歇根湖北部及绿湾的28个位点部署了营养扩散基质（Nutrient Diffusing Substrata, NDS），设置对照组、加氮组、加磷组及氮磷共同添加组四种处理。对照组NDS杯仅含重量百分比为2%的琼脂；加氮组、加磷组及氮磷共同添加组则分别在琼脂中添加0.5 M氯化铵（NH4Cl）、0.5 M磷酸二氢钾（KH2PO4）或两者的混合物。实验于2017年7月11日至31日部署，28至29天后（2017年8月8日至28日）回收。附生植物生物量数据（以叶绿素a及无灰干重（AFDW）计）存储于文件"NDS_Chl_AFDW.csv"中；位点位置及环境参数（包括水柱营养浓度、Kd值与叶绿素含量）则记录在"SITES_PARAMETERS"文件内。