Stream biofilm response to nutrient enrichment in urbanizing streams: nutrient diffusing substrate bioassay

This resource contains the results of an experiment to test the effects of nutrients on stream biofilms at montane and urban sites in the Logan River, Red Butte Creek, and Middle Provo River watersheds located in northern Utah. We tested the effects of individual nitrogen and phosphorus additions and combined nitrogen and phosphorus additions at a series of concentrations on biofilm biomass using nutrient diffusing substrates (NDS). The Word document "methods_NDS" describes the methods used to construct the NDS and treatments included in our experiment.

At the end of the deployment period, biofilms grown on NDS were frozen. We measured chlorophyll a on half of the replicates and measured ash-free dry mass on the other half. The CSV file “biomass_nutrients_NDS” contains summary statistics (mean, standard deviation, count) of chlorophyll a concentrations and ash-free dry mass of biofilms on each nutrient treatment at our study sites. The Word document “methods_NDS” describes the analytical methods used to measure chlorophyll and ash-free dry mass.

We collected water column samples at each site for total and dissolved nutrient analyses. The CSV file “biomass_nutrients_NDS” contains total nitrogen, total phosphorus, ammonium, nitrate, and soluble reactive phosphorus concentrations at each site. The Word document “methods_NDS” describes the analytical methods used to measure nutrient concentrations.

本资源收录了在犹他州北部洛根河、红山溪和米德普罗沃河流域的山地与城市地点进行的实验结果，旨在检验营养素对溪流生物膜的影响。本研究通过营养扩散基质（NDS）在一系列浓度下对生物膜生物量进行氮和磷单独添加及复合添加的效应进行测试。‘methods_NDS’ Word文档详细描述了NDS的构建及实验中包含的处理方法。

实验部署期结束后，NDS上生长的生物膜被冷冻保存。我们对一半的重复样本进行了叶绿素a的测量，另一半则测量了无灰干燥质量。‘biomass_nutrients_NDS’ CSV文件包含了各营养处理组在研究地点的生物膜叶绿素a浓度和无灰干燥质量的汇总统计数据（平均值、标准差、计数）。‘methods_NDS’ Word文档描述了测量叶绿素和无灰干燥质量的分析方法。

我们在每个地点采集了水柱样本以进行总营养素和溶解营养素的分析。‘biomass_nutrients_NDS’ CSV文件包含了每个地点的总氮、总磷、铵、硝酸盐和溶解性活性磷的浓度。‘methods_NDS’ Word文档描述了测量营养素浓度的分析方法。