https://doi.org/10.5061/dryad.83bk3j9t1

Description of the data and file structure

File list (files found within DataS1.zip)

brown_et_al_2024_data.xlsx

brown_et_al_2024_impound_wc.csv

brown_et_al_2024_indep_var_values.csv

brown_et_al_2024_spearman_indep_vars.csv

brown_et_al_2024_depend_var_descriptions.csv

brown_et_al_2024_depend_var_up-down_values_and_fract_diffs.csv

brown_et_al_2024_bray_curtis_similarities.csv

File descriptions

brown_et_al_2024_data.xlsx - Supporting data for Brown et al. 2024. Data files in the tabs in the Excel file are also provided as .csv files and are described below. Blank cells in all data tabs indicate missing values.

Brown_et_al_2024_impound_wc.csv - Impoundment water chemistry profiles and stratification information. Data for the Gunpowder River (GUNP) was obtained from the City of Baltimore, which owns and monitors Prettyboy Reservoir; site GUN0339 is at the gatehouse, affixed to the dam; site GUN0401 is 305 m upstream. Each impoundment is identified by its site code (Table 2, Brown et al 2024). DO (mg/L) for HOPE and SUNR were not recorded when measurements were taken; they were calculated from DO% and Temp (C), but not corrected for depth. DO% for GUNP sites was not corrected for depth.

brown_et_al_2024_indep_var_values.csv - Descriptions and values of independent variables. Blank cells indicate missing values.

brown_et_al_2024_spearman_indep_vars.csv - Spearman correlations of independent variables related to impoundment or watershed characteristics. Spearman correlation coefficients are above with italicized P values below them; significant relationships are in bold. “Diff.” refers to downstream minus upstream differences. All variables were log-transformed prior to being correlated (though this does not affect results with Spearman correlations).

brown_et_al_2024_depend_var_descriptions.csv - Description of dependent variables.

brown_et_al_2024_depend_var_up-down_values_and_fract_diffs.csv - Values of dependent variables used for analysis and fractional differences. See Brown_et_al_2024_depend_var_descriptions.csv for description of variables. Downstream-minus-upstream fractional differences were calculated as 2*(downstream value – upstream value)/(downstream + upstream value), except for downstream-upstream species compositional similarity coefficients, which we calculated for each taxonomic group (periphyton, macroinvertebrates, fish, and plants) using Bray-Curtis similarity. Difference values for dependent variables used to calculate the multiple regression values shown in Table 3 in Brown et al 2024. Fish sampling was not done at all sites because of budget limitation, inability to effectively sample some sites and occurrence of other dams in the drainage. Blank cells indicate missing values.

brown_et_al_2024_bray_curtis_similarities.csv - Bray Curtis percent similarities for periphyton, macroinvertebrates, fish, and riparian plants. FP - Flood plain; UP = Upland. Blank cells indicate missing values.

The files in this dataset include descriptions and values of measured variables used in analyses, chemistry and stratification information on impoundments, and upstream-downstream Bray-Curtis Similarity values for biota studied. The readme.txt file describes individual data files. Data are in both the .xlsx file and in individual .csv files. Blank cells in the files indicate missing values. Data can be used to re-evaluate study results and for new studies on the influence of dams on rivers.