This codebook.txt file was generated on <2017-09-06> by Christy Dolph ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: Characterization of streams and rivers in the Minnesota River Basin Critical Observatory: water chemistry and biological field collections, 2013-2016 2. Author Information: Christine Dolph, Amy Hansen, Katie Kemmit, Benjamin Janke, Sarah Winikoff, Evelyn Boardman, Anna Baker, Michelle Rorer & Jacques Finlay Principal Investigator Contact Information Name: Jacques Finlay Institution: Department of Ecology, Evolution and Behavior, University of Minnesota Address: 140 Gortner, 1479 Gortner Ave, St. Paul, MN 55108 Email: jfinlay@umn.edu 3. Date of data collection: 2013-05-15 - 2016-11-30 4. Geographic location of data collection: South and west-central Minnesota Bounding Coordinates (Projected; NAD1983 / UTM zone 15N): 4831451 5106922 480061 268661 5. Information about funding sources that supported the collection of the data: National Science Foundation under Grant No. 1209402 Water, Sustainability and Climate (WSC) – Category 2, Collaborative: Climate and human dynamics as amplifiers of natural change: a framework for vulnerability assessment and mitigation planning. National Science Foundation under Grant EAR-1415206 Science, Engineering and Education for Sustainability (SEES) Fellows to A.T.H.: SEES Fellows: Leveraging the waterscape to increase agricultural landscape sustainability. Minnesota Department of Agriculture under Grant No. 92036, Measuring and modeling watershed phosphorus loss and transport for improved management of agricultural landscapes. Project dollars provided by the Clean Water Fund (from the Clean Water, Land and Legacy Amendment). -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: 2a. Links to publications that cite or use the data: Dolph, C.L., Hansen, A.T. & Finlay, J.C. 2017. Flow-related dynamics in suspended algal biomass and its contribution to suspended particulate matter in an agricultural river network of the Minnesota River Basin, USA. Hydrobiologia 785: 127. DOI:10.1007/s10750-016-2911-7 Hansen, A. T., Dolph, C.L. & Finlay, J.C. 2016. Do wetlands enhance downstream denitrification in agricultural landscapes? Ecosphere 7(10):e01516. DOI: 10.1002/ecs2.1516 2b. References: Griffis, T.J., Wood, J.D., Baker J.M., Lee, X., Xiao, K., Chen, Z., Welp, L.R., Schultz, N.M., Gorski, G., Chen, M. & Nieber, J. 2016. Investigating the source, transport, and isotope composition of water vapor in the planetary boundary layer. Atmospheric Chemistry and Physics 16:5139-5157. Hood, E., Gooseff, M.N., & Johnson S.L. 2006. Changes in the character of stream water dissolved organic carbon during flushing in three small watersheds, Oregon, Journal of Geophysical Research, 111, G01007, doi:10.1029/2005JG000082 Nilsson, M., Korsman, T., Nordgren, A., Palmborg, C., Renberg, I., OÈhman, J. 1992 NIR spectroscopy used in the microbial and environmental sciences. In: Hildrum KI, Isaksson T, Naes T, 181 Tandberg A (eds) Near-infrared spectroscopy. Ellis Horwood, London, pp 229-234 Whittinghill, K.A., Finlay, J.C. & Hobbie, S.E. 2014. Bioavailability of dissolved organic carbon across a hillslope choronsequence in the Kuparuk River region, Alaska. Soil Biology and Biogeochemistry 79: 25-33. Groffman, P.M., Butterbach-Bahl, K., Fulweiler, R.W., Gold, A.J., Morse, J.L., Stander, E.K., Tague, C., Tonitto, C. & Vidon, P. 2009. Challenges to incorporating spatially and temporally explicit phenomena (hotspots and hot moments) in denitrification models. Biogeochemistry 93:49-77. Inwood, S.E., Tank, J.L. & Bernot, M.J. 2007. Factors controlling sediment denitrification in midwestern streams of varying land use. Microbial Ecology 53: 247-258. Loken, L.C., Small, G.E., Finlay J.C., Sterner, R.W. & Stanley, E.H. 2016. Nitrogen cycling in a freshwater estuary. Biogeochemistry 127: 199-216. McCrackin, M.L. & Else J.J. 2010. Atmospheric nitrogen deposition influences denitrification and nitrous oxide production in lakes. Ecology 91: 528-539. Gore, J.A. 2006. Discharge measurements and streamflow analysis, p. 53-74. In Hauer, F.R. & Lamberti G.A. (eds). Methods in Stream Ecology, Academic Press, San Diego. 3. Links to other publicly accessible locations of the data: 4. Links/relationships to ancillary data sets: 5. Was data derived from another source? Yes If yes, list source(s): Watershed areas draining to study sites were derived from National Hydrography Dataset and 30m Digital Elevation Model 6. Recommended citation for the data: Dolph C, Hansen A, Kemmit K, Janke B, Winikoff S, Boardman E, Baker A, Rorer M & Finlay J. 2017. Chracterization of streams and rivers in the Minnesota River Basin Critical Observatory: nutrients, sediment, hydrology and biology from field sites in the Le Sueur, Chippewa and Cottonwood River Basins, 2013-2016. University of Minnesota. University of Minnesota Digital Conservancy. doi: --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: MRB_Water_Chem_2013_2016.txt Short description: Water chemistry data collected from ditches, streams, rivers and wetlands of the Minnesota River Basin, 2013-2016 B. Filename: Stable_Isotopes_d13C_d15N.txt Short description: Stable isotope values (Carbon-13, Nitrogen-15) of seston, basal resources, and macroinvertebrates collected from ditches, streams and rivers of the Minnesota River Basin, 2013-2015. C. Filename: Denitrification_and_sediment_characteristics.txt Short description: Denitrification rates and sediment characteristics from benthic sediments collected from agricultural drainage ditches in the Le Sueur River Basin, 2014-2015. D. Filename: Stream_discharge_2013_2015.txt Short description: Stream discharge measured at a subset of study sites in the Le Sueur River Basin, 2013-2015. E. Filename: MRB_study_sites.gdb Short description: Spatial point locations for ditch, stream, river and wetland study sites in the Minnesota River Basin sampled for water chemistry and other parameters, 2013-2016. F. Filename: MRB_site_watersheds.gdb Short description: Watershed areas delineated for all ditch, stream and river study sites sampled in the Minnesota River Basin, 2013-2016. 2. Relationship between files: Samples in all files were collected from same set of study sites; unique sites are identified in Site_ID column. 3. Additional related data collected that was not included in the current data package: N/A 4. Are there multiple versions of the dataset? yes/no NO -------------------------- METHODOLOGICAL INFORMATION -------------------------- A. File: MRB_Water_Chem_2013_2016.txt Samples in the water chem dataset (‘MRB_Water_Chem_2013_2016.txt’) were collected as described in Hansen et al., 2016 and Dolph et al., 2017. Sampling dates at various sites spanned a range of seasonal and flow conditions, including low flows and record high flows. Whole water samples were collected from each site in acid-washed Nalgene bottles that were rinsed twice with site water prior to sample collection. Samples were collected from the middle of stream and river channels, just below the water surface, without disturbing the benthos. Samples with ‘_Tile’ in the Site ID column were collected directly from actively draining tile drain pipes at the corresponding study site (i.e., prior to mixing with water in the channel). All samples were transported back to the lab on ice. Water samples were processed in the laboratory for total dissolved nitrogen (TDN), nitrate (NO3-N), nitrite (NO2-N), ammonium (NH4+-N), particulate nitrogen (PN), total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP), particulate phosphorus (PP), particulate carbon (PC), dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), chlorophyll-a (Chla), total suspended solids (TSS), volatile suspended solids (VSS), delta-H-2 and delta-O-18 stable isotopes of site water, and specific ultraviolet absorbance (SUVA) and fluorescence index (FI) of site water. Analyses were carried out in laboratories at the University of Minnesota (UMN), unless otherwise noted. All samples except TSS were processed (i.e., filtered) within 24 h of collection; TSS samples were kept in the dark at 4˚C and typically processed within several days of collection. Samples used for the analysis of dissolved constituents were filtered through pre-ashed GF/F glass fiber filters with a nominal pore size of 0.7 μm (Whatman, Kent, UK). Water samples for TDN and DOC were acidified with 2 N HCl to pH 2 and kept at 4°C until analyzed using a Shimadzu TOC V CPN Analyzer (Shimadzu Scientific Instruments, Columbia, Maryland, USA), which was also used to analyze DIC samples. DIC samples were stored with headspace in the vials and kept at 4°C until analysis, and therefore dissolved CO2 was likely in equilibrium with laboratory air before processing. SRP and TDP filtrates were frozen prior to analysis. SRP was analyzed by molybdate colorimetry, and TDP was analyzed using the same method after persulfate digestion. NO3 samples were frozen prior to analysis then analyzed using cadmium reduction to NO2 followed by colorimetric analysis with a Lachat Quickchem FIA (Hach Company, Loveland, Colorado, USA). NH4 was analyzed by colorimetric analysis using a Lachat Quickchem FIA. For particulate analyses (except for Chla), samples were obtained from filtering through pre-ashed 0.7 micron Whatman GF/F filters. Chla was obtained from filtration using 25 micron cellulose nitrate filters and the standard fluorometric method with 90% acetone extraction (Welschmeyer, 1994). PP was analyzed from the filters using molybdate colorimetry, similar to TDP, while PN and PC were determined using near infrared spectrophotometry (NIRS) (Hood et al., 2006), which was calibrated through comparison with PN and PC measurements from a CHN analyzer (Perkin Elmer, Waltham, Massachusetts, USA) on a subset of samples (Nilsson et al. 1992). TSS filters were dried at 60˚C, and then weighed to determine the mass of total suspended solids. Filters were then ashed at 550˚C and re-weighed to determine the mass of volatile suspended solids. Stable isotope composition of sample water (delta-H-2 and delta-O-18) were measured as described by Griffis et al., 2016. In brief, an off-axis cavity ring-down infrared laser spectroscopy system (DLT-100 Liquid Water Analyzer, Los Gatos Research, Inc., Mountain View, CA) coupled to an autosampler (HT-300A, HTA s.r.l., Brescia, Italy) was used for simultaneous measurements of delta-H-2 and delta-O-18. Six replicates were run per sample; final delta-H-2 and delta-O-18 values were calculated as means across replicates. Measurement precision using instrument was ±1.0 ‰ for delta-H-2 and ±0.25 ‰ for delta-O-18. Precalibrated laboratory standards were used to calibrate the unknown samples to the Vienna Standard Mean Ocean Water scale, and were selected based on the expected isotope composition of the unknown samples. Standards were injected after every two unknown samples to correct for instrumental drift. Linear calibration equations were calculated using each set of standards throughout the autorun and used to correct unknown samples. We measured SUVA and FI of site water using the methods described by Whittinghill et al., (2014). UV absorbance was measured using a spectrophotometer (Cary 50 UVeVis Spectrophotometer, Varian, Palo Alto, CA). SUVA was calculated by dividing UV absorbance of site water at a 254nm by the concentration of DOC in the sample. FI was calculated as emission at 470 nm divided by emission at 520 nm of site water DOM excited at 370 nm using a fluorimeter (Horiba Scientific, FluoroMax-3 Spectrofluorimeter, Edison, NJ). Where replicate samples of water chemistry were collected for a given sampling visit to a study site, water chemistry results were averaged to achieve final result. B. File: Stable_Isotopes_d13C_d15N.txt Stable isotopes (δ13C, d15N) of suspended organic matter (i.e., seston), macroinvertebrates and basal food sources (found in the file ‘Stable_Isotopes_d13C_d15N.txt’) were collected from a subset of study sites as described by Dolph et al. (in review). Eight types of basal resources were collected at each study site: seston, leaves, wood, fine particulate organic matter (FPOM, defined as benthic detritus < 1mm in size), coarse particulate organic matter (CPOM, defined as benthic detritus > 1mm in size), maize, benthic algae (filamentous growths), and biofilm (epilithic material). Seston was collected by taking a bulk water sample from the center of the study reach prior to any disturbance of the benthos. For all other resource types, we collected three subsamples of each type by hand from the start, middle and end of the 50m study reach at each site. All resource types, including terrestrial litter (leaves, wood, maize), were collected from within the stream (as opposed to live material collected from the banks), and exhibited varying levels of physical breakdown and microbial processing. We sought to collect all subsamples from riffles or runs (not pools). Leaf samples included multiple common species found at each site. Benthic algae samples were macroalgae sufficiently large to be removed from rocks or wood; these macroscopic algae samples were often covered in diatoms that could not be removed by rinsing. Biofilm was sampled by scrubbing the upper surface of coarse substrate (a stone or in some cases wood if no stones were available) with a toothbrush. CPOM was benthic organic material that had been poured through and retained on a 1 mm sieve; FPOM was the benthic matter that passed through the same sieve. Samples were transported to the laboratory at ~4˚C, where they were picked clean of non-target debris, rinsed 3x with Nanopure water, dried homogenized and weighed. In 2014, some organic matter samples were frozen for 30-60 days prior to drying. For seston, bulk water samples were filtered through pre-combusted 0.7 μm Whatman glass fiber filters and dried (Whatman, Kent, UK). Filters were fumed with 0.5N hydrochloric acid prior to analysis to remove inorganic carbon. Macroinvertebrates were sampled from a 100m stream reach at each study site using a kick-net (mesh size 500μm). Collected specimens were kept at 4˚C for 24 hours to clear their guts, sorted to the lowest possible taxonomic order (typically genus or family), rinsed 3x with Nanopure water, dried, homogenized and weighed. Except for larger taxa, most consumer samples represented the aggregate of multiple individual specimens collected during the sampling visit, to generate sufficient mass for stable isotope analysis. The number of individual specimens per sample ranged from 1 to 200, depending on the taxon. For taxa with carbonate-containing shells or exoskeletons (i.e., snails, amphipods, crayfish), sample tissue was either dissected (snails) or rinsed in a 0.5N HCl solution (amphipods and crayfish) prior to rinsing and drying, to remove carbonates. In 2013 and 2014, macroinvertebrate samples were preserved in 70% ethanol for ~30-60 days prior to rinsing, drying and weighing; in 2015, no preservative was used, and samples were rinsed and then dried fresh. In 2015, we also preserved a subset of samples in 70% ethanol for 90 days prior to drying, to evaluate the effect of sample preservation on stable isotope values. The preservation method for each basal resource sample (including seston) and each invertebrate sample is described in the ‘Presevation.Method’ column in the dataset. All basal resources and macroinvertebrate samples were analyzed for δ13C, δ15N and C:N at the Colorado Plateau Stable Isotope Laboratory (Flagstaff, Arizona, USA). C. File: Denitrification_and_sediment_characteristics.txt Sediment samples were collected from agricultural drainage ditches in the Le Sueur River Basin as described in Hansen et al., (2016). Rinsed plastic tubes of 28 cm2 cross-sectional area were used to collect sediment cores to a depth of five cm (Inwood et al. 2007). At each site, five sediment cores were collected approximately every 10 m, and then composited. Sediment samples were always collected upstream of rip rap and culverts to avoid ponding effects on sediment organic composition. Sediment samples were transported back to the lab at 4˚C within 24 hours of collection, and used to estimate benthic sediment characteristics and denitrification rates of benthic sediment. Benthic sediment organic matter content, bulk density (i.e., dry weight per unit volume) and the ratio of dry weight to wet weight were determined for all composite sediment samples. Twenty mL of wet sediment was weighed, and then dried at 60°C. Subsamples of dried sediment (1 g) were ashed at 550 °C for 2 hours and weighed to determine organic matter content as mass loss on ignition. Denitrification rates were assessed in the laboratory using the acetylene block technique as modified from Groffman et al. (2009) as described in Loken et al. (2016). Samples were incubated with unamended site water or with site water amended with N, P, and C as in (McCrackin and Elser 2010). Slurries of site sediment and site water were purged with He gas before incubation in airtight glass bottles. Chlorophenical was added to all samples to prevent microbial reproduction. N2O accumulation over time was assessed with gas chromatograph analysis of gas samples taken from the sealed bottle at 20 minutes after purging and again approximately two hours after the first sample. Gas samples were prepared by injecting 5ml of gas from the incubation bottle headspace into a previously helium-flushed autosampler vial (10 mL). The gas samples were analyzed on a customized gas chromatography system (HP5890 GC), which was interfaced to an automated headspace sampler (HP7694). N2O was separated from the sample by packed column (1/8” x 6’: Porapak Q) and quantified by comparing the response of the N2O peak from the electron capture detector (Ar/CH4 makeup/carrier flow) to certified gas standards (Toll Gas; Plymouth, MN). Samples with greater than 6% oxygen content were not included in subsequent analysis if their N2O production rate varied from the replicate sample by more than 20%. Blank vials and blank bottles were run with each batch to verify that no systemic oxygen contamination occurred during the incubation process. Measured N2O gas production rates were normalized by sediment bulk density and are reported as areal denitrification rates, U-DEN (mg-N m-2 hr-1). D. File: Stream_discharge_2013_2015.txt Stream discharge was measured as described in Dolph et al., 2017. Stream discharge was calculated using the velocity-area method (Gore 2006). Velocity measurements were taken at 0.6 water depth at 1 Hz frequency for 45 sec at each location using an acoustic Doppler velocimeter (Flowtracker, Sontek/YSI). Discharge calculations were completed with the average streamwise component of the velocity vector. Measurements were repeated if the signal to noise ratio was less than 20 or if more than 2 spikes were present. Total cross sectional area was calculated as the sum of each subsection in which velocity was measured. The shape of each subsection was modeled as trapezoidal for the purpose of discharge calculations. E. File: MRB_study_sites.gdb This geodatabase contains coordinate locations for study sites, together with associated site information in the attribute table. Site coordinates were identified with a Garmin GPS at the sampling location. Sites were designated as lake or wetland “outlets” if they were located immediately downstream of a lake or palustrine wetland and prior to any additional network inputs. Using the Minnesota Department of Natural Resources update of the National Wetland Inventory dataset, ‘lakes’ are defined as water features larger than 80,000 m2 that are characterized by deep water habitat (>2 m depth) and/or littoral habitats characteristic of lacustrine systems. Smaller water bodies (<80,000 m2 in size) were also considered ‘lakes’ if at least a portion of their boundary was active wave-formed shoreline or bedrock. Palustrine ‘wetlands’ were defined as <80,000 m2, and with a depth <2 m (MNDNR, 2015). F. File: MRB_study_watersheds.gdb This geodatabase contains watershed areas delineated for all study sites. See the readme file for definitions of all columns in the attribute tables. We determined watershed areas (i.e., the land area draining into each study site) by applying Arc Hydro watershed delineation tools in ArcGIS to 30-m resolution digital elevation models. Prior to delineation, the stream network from the National Hydrography Dataset (NHD) was burned into the DEM (burn depth=10m). ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: MRB_Water_Chem_2013_2016.txt ----------------------------------------- 1. Number of variables: 27 2. Number of cases/rows: 904 3. Missing data codes: 'NA' = no data collected 'bdl' = below detection limit; detection limit for NO3, NO2 and NH4 was 10 ug/L; detection limit for Chla was 0.05 ug/L 4. Variable List A. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in spatial data and other files. Note: Samples with '_Tile' in the SiteID indicates water was collected from tile drains at the corresponding study site. B. Name: Date Description: Date samples were collected in the field. C. Name: TDN Description: Total dissolved nitrogen concentration of site water (mg/L) D. Name: NO3 Description: Nitrate concentration of site water (mg/L), detection limit = 0.010 mg/L E. Name: PN_NIRS Description: Particulate nitrogen concentration of site water (mg/L) as measured via near infrared spectrophotometry F. Name: PN_CHN Description: Particulate nitrogen concentration of site water (mg/L) as measured via CHN analyzer G. Name: NO2 Description: Nitrite concentration of site water (mg/L), detection limit = 0.010 mg/L H. Name: NH4 Description: Ammonium-N concentration of site water (mg/L), detection limit = 0.010 mg/L I. Name: TDP Description: Total dissolved phosphorus concentration of site water (ug/L) J. Name: SRP Description: Soluble reactive phosphorus concentration of site water (ug/L) K. Name: PP Description: Particulate phosphorus concentration of site water (ug/L) L. Name: TP Description: Total phosphorus concentration of site water (ug/L) M. Name: TSS Description: Total suspended solids (inorganic + organic) of site water (mg/L) N. Name: VSS Description: Volatile suspended solids (organic matter) of site water (mg/L) O. Name: Chla Description: Chlorophyll a concentration of site water (ug/L), detection limit = 0.05 ug/L P. Name: PC_NIRS Description: Particulate carbon concentration (inorganic + organic) of site water (ug/L), as measured by near infrared spectroscopy Q. Name: PC_CHN Description: Particulate carbon concentration (inorganic + organic) of site water (ug/L), as measured by CHN analyzer R. Name: FI Description: S. Name: UV.ABS.254.00nm.SUVA Description: Specific ultraviolet absorbance by site water of ultraviolet light at a wavelength of 254nm, normalized for dissolved organic carbon concentration; replicate 1 T. Name: UV.ABS.254.00nm.SUVA.2 Description: Specific ultraviolet absorbance by site water of ultraviolet light at a wavelength of 254nm, normalized for dissolved organic carbon concentration; replicate 2 U. Name: UV.ABS.254.00nm.SUVA.3 Description: Specific ultraviolet absorbance by site water of ultraviolet light at a wavelength of 254nm, normalized for dissolved organic carbon concentration; replicate 3 V. Name: DOC Description: Dissolved organic carbon concentration of site water (mg/L) W. Name: DIC Description: Dissolved inorganic carbon concentration of site water (mg/L) X. Name: dD Description: Ratio of hydrogen stable isotopes deuterium (hydrogen-2) to protium (hydrogen-1) in site water, reported in permil relative to Vienna Standard Mean Ocean Water Y. Name: dD_stdv Description: Standard deviation of the dD value of site water across 6 replicates Z. Name: dO18 Description: Ratio of the oxygen stable isotopes oxygen-18 to oxygen-16 in site water, reported in permil relative to Vienna Standard Mean Ocean Water AA. Name: dO18_stdv Description: Standard deviation of the dO18 value of site water across 6 replicates ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Stable_Isotopes_d13C_d15N.txt ----------------------------------------- 1. Number of variables: 14 2. Number of cases/rows: 1021 3. Missing data codes: "NA" = No data collected 4. Variable List A. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in spatial data and other files. B. Name: Date Description: Date samples were collected in the field. C. Name: Sample_type Description: Type of sample collected 'invert' = macroinvertebrate sample 'organic matter' = potential basal endmember food resource 'POC' = suspended organic water (i.e., seston) D. Name: Sample_ID Description: Specific sample identity; for invertebrate samples, Sample_ID represents the most specific taxonomic ID obtained; for organic matter samples, Sample_ID represents specific type of basal resource collected E. Name: Order Description: Name of taxonomic order for invertebrate taxa F. Name: Family Description: Name of taxnomic family for invertebrate taxa G. Preservation.Method Description: Methods used to preserve biological samples (invertebrate or organic matter) H. Name: Mass Description: mass of dried sample (in grams) I. Name: d13C Description: stable carbon isotope value of sample J. Name: d15N Description: stable nitrogen isotope value of sample K. Name: Pct_C Description: Percent contribution of carbon to total sample mass L. Name: Pct_N Description: Percent contribution of nitrogen to total sample mass M. Name: C.N.ratio Description: mass ratio of carbon to nitrogen in sample ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Denitrification_and_sediment_characteristics.txt ----------------------------------------- 1. Number of variables: 8 2. Number of cases/rows: 76 3. Missing data codes: "NA" = No data collected 4. Variable List A. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in spatial data and other files. B. Name: Date Description: Date samples were collected in the field. C. Name: POT DEN (mg N2O-N/m2/hr) Description: POT DEN is the average areal denitrification rate measured with amended site water across two replicates. Data was verified to not include negative numbers. Rates were calculated using measured dw:ww and measured bulk density for this sediment sample. When these sediment characteristics were not available, a time averaged value for that site was used instead. D. Name: ACT DEN (mg N2O-N/m2/hr) Description: ACT DEN is the average areal denitrification rate measured with unamended site water across two replicates. Data was verified to not include negative numbers. Rates were calculated using measured dw:ww and measured bulk density for this sediment sample. When these sediment characteristics were not available, a time averaged value for that site was used instead. E. Name: Sediment dw:ww Description: Sediment dw:ww is the ratio of sediment weighed dry to sediment weighed wet. F. Name: Sediment Bulk Density (g/cm3) Description: Sediment bulk density is sediment dry weight per unit volume G. Name: Sediment Soil Moisture (%) Description: Sediment soil moisture is the percent of sediment wet weight that is attributed to water content. H. Name: Sediment Organic Matter Content (%) Description: Sediment organic matter content was calculated as the percent of dry sediment mass that was lost on ignition ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Stream_discharge_2013_2015.txt ----------------------------------------- 1. Number of variables: 7 2. Number of cases/rows: 67 3. Missing data codes: "NA" = No data collected 4. Variable List A. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in spatial data and other files. B. Name: Date Description: Date samples were collected in the field. C. Name: Q (L/s) Description: Q is water discharge reported in units of Liters/second. D. Name: Total cross-sectional area (m2) Description: Total cross-sectional area is the sum of the measured sub-sectional areas (m2) E. Name: Max Depth (cm) Description: Max depth (cm) is the maximum measured depth of the cross-section. Note that this is not an absolute maximum depth. F. Name: Width (cm) Description: Width of cross-section (cm). G. Name: Temp (deg C) Description: Water temperature (degrees Celsius) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: MRB_study_sites.gdb ----------------------------------------- 1. Number of variables: 11 2. Number of cases/rows: 231 3. Missing data codes: Blank = not applicable 4. Variable List A. Name: OBJECTID Description: unique ObjectID field B. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in water chemistry and other files C. Name: Shape Description: Type of shape D. Name: UTMx Description: x coordinate of study sites in UTM (Projection: NAD 1983 Zone 15N) E. Name: UTMy Description: y coordinate of study sites in UTM (Projection: NAD 1983 Zon 15N) F. Name: Long_DD Description: x coordinate of study sites in decimal degrees G. Name: Lat_DD Description: y coordinate of study sites in decimal degrees H. Name: Basin Description: major river basin (HUC8) in which study site is located 'LS' = Le Sueur River Basin 'CO' = Cottonwood River Basin 'CH' = Chippewa River Basin 'CA' = Cannon River Basin 'WA' = Wantonwan River Basin 'BE' = Blue Earth River Basin I. Name: Outlet_typ Description: indicates if site is within or immediately downstream of a standing water body, and whether that water body is a lake or wetland 'internal lake' = sample was collected from inside boundaries of a lake or wetland 'lake' = sample was collected immediately downstream from a lake 'wetland' = sample was collected immediately downstream from a wetland 'not on network' = sample was collected from water body not connected to stream or river network blank values = samples collected from stream and river channels not immediately downstream from a wetland or lake J. Name: Inlet_type Description: indicates if site is immediately upstream of a standing water body, and whether that water body is a lake or wetland K. Name: Gage Description: indicates whether discharge (Q) was measured at study site ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: MRB_site_watersheds.gdb ----------------------------------------- 1. Number of variables: 5 2. Number of cases/rows: 231 3. Missing data codes: 4. Variable List A. Name: OBJECTID Description: unique ObjectID field B. Name: Site_ID Description: Unique study site ID; corresponds to Site_ID columns in water chemistry and other files C. Name: Shape Description: Type of shape D. Name: Shape_Length Description: length of watershed polygon in meters E. Name: Shape_Area Description: area of watershed polygon in squared meters