Stream biofilm diphenhydramine dose-response experiment

This resource contains the results of a diphenhydramine dose-response experiment conducted on stream biofilms at a site on the Logan River in northern Utah. We grew stream biofilms on inorganic (fritted glass disc) and organic (cellulose sponge) substrates in the river for 20 days. The biofilm-colonized substrates were then placed as caps on contaminant exposure substrates (CES), 1-oz plastic cups filled with agar amended with diphenhydramine at a series of concentrations (control, 0.5 mM, 0.75 mM, 1.25m M, 2.5 mM, 15 mM). CES were then deployed in the river for 20 days. At the end of the CES deployment, the biofilm-colonized substrates were used to perform a series of in-stream incubations. We measured respiration and productivity using a modified light-dark bottle incubation method and nitrogen fixation rates using an acetylene reduction assay. We measured biofilm biomass (chlorophyll a, ash-free dry mass) and calculated Autotrophic Index values (calculated as chlorophyll a concentration divided by ash-free dry mass). The CSV file “biomass_function_diphenhydramine” contains summary statistics (mean, standard deviation, count) of respiration rates, gross primary production rates, nitrogen fixation rates, chlorophyll a concentrations, ash-free dry mass, and Autotrophic Index values of biofilms on each diphenhydramine treatment and substrate type. The Word document “methods_diphenhydramine” describes the analytical methods used to measure chlorophyll and ash-free dry mass. We characterized light availability and nutrient concentrations at the study site. The Word document “methods_diphenhydramine” describes the methods used to measure site characteristics and the analytical methods used to measure nutrient concentrations. The CSV file “site_characteristics_diphenhydramine” contains percent canopy openness, transmitted PAR, transmitted solar shortwave radiation, total nitrogen, total phosphorus, ammonium, nitrate, soluble reactive phosphorus, dissolved total iron, and dissolved ferrous iron concentrations.本数据集包含美国犹他州北部洛根河某点位开展的溪流生物膜苯海拉明（diphenhydramine）剂量反应实验结果。研究人员将溪流生物膜分别接种于无机基质（烧结玻璃圆盘）与有机基质（纤维素海绵）上，于河道中培育20天。随后将定植有生物膜的基质作为顶盖安装于污染物暴露基质（Contaminant Exposure Substrates，CES）之上；该基质为填充有添加了系列梯度浓度苯海拉明琼脂的1盎司塑料杯，浓度梯度包括对照组、0.5 mM、0.75 mM、1.25 mM、2.5 mM及15 mM。随后将组装完成的污染物暴露基质投放至河道中，培育20天。 污染物暴露基质投放结束后，利用定植有生物膜的基质开展一系列河道原位培养实验。研究人员采用改良的明暗瓶培养法测定生物膜呼吸速率与生产力，采用乙炔还原法测定固氮速率。测定了生物膜生物量（叶绿素a、无灰干重），并计算自养指数（Autotrophic Index）值，该指数以叶绿素a浓度与无灰干重的比值计算得到。CSV格式文件"biomass_function_diphenhydramine"包含各苯海拉明处理组及基质类型下生物膜的呼吸速率、总初级生产力、固氮速率、叶绿素a浓度、无灰干重及自养指数值的汇总统计量（均值、标准差、样本量）。Word文档"methods_diphenhydramine"详细说明了用于测定叶绿素与无灰干重的分析方法。 研究人员对研究点位的光照可用性与营养盐浓度进行了表征。前述Word文档"methods_diphenhydramine"同时说明了用于测定研究点位特征的方法，以及用于测定营养盐浓度的分析方法。CSV格式文件"site_characteristics_diphenhydramine"包含冠层开度百分比、透射光合有效辐射（Photosynthetically Active Radiation，PAR）、透射太阳短波辐射、总氮、总磷、铵态氮、硝态氮、可溶性活性磷、溶解态总铁及溶解态亚铁浓度。