DOI: 10.20350/digitalcsic/8588
title: Methane emissions in Doñana saltmarshes over 2016‐2018

description: This data set includes measurements of water samples collected from 7 sites during 16 surveys carried out between March 2016 and March 2018 in the salt marshes of Doñana National Park. Geographic coordinates of sampling positions are provided. During samplings, in situ water conductivity (converted to salinity), temperature and pH were measured using a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA) and water samples were collected for laboratory analysis of dissolved methane and nitrous oxide by static‐head space equilibration gas chromatography (GC) using an Agilent 7890 GC equipped with Flame Ionization Detector (FID) for CH4, according to de la Paz et al. (2015). Samples were also taken for analysis of phosphate, nitrate, nitrite and ammonia (with a Skalar Sanˆ++215 Continuous Flow Analyzer and using the standard colorimetric techniques described in Hansen and Koroleff 1999), dissolved oxygen and total alkalinity (using a Metrohm 794 Titroprocessor following the methods described by Mintrop et al. (2000) and Winkler) and dissolved organic carbon and total dissolved nitrogen that were determined through by catalytic oxidation at high temperature (720 °C) and chemiluminescence, respectively in a Shimadzu Total Organic Carbon analyzer (Model TOC‐VCPH/CPN), according to Álvarez‐Salgado and Miller (1998). Dissolved carbon dioxide partial pressure was calculated from pHNBS and total alkalinity using co2sys.xls (Pierrot et al., 2000) with the dissociation constants for carbon and sulfate of (Cai and Wang 1998) and (Dickson 1990), respectively.
description: Calculations of the equilibrium concentrations of methane and nitrous oxide in the water phase was done using the annual averaged atmospheric mixing ratios CH4 (xCH4atm) provided by the World Data Center for Greenhouse Gases (http://ds.data.jma.go.jp/gmd/wdcgg/). Such mean value during the sampling period was calculated as 1866 ppb.
description: Daily measurements of rainfall (mm), air temperature (ºC) and wind speed (m s‐1) were provided by ameteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34” W) managed by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController). The data is provided as [space] delimitated plain text files within a compressed folder that also includes a single README file (in PDF format) containing a detailed description of the data structure.
description: For more details, see the publication: I. Emma Huertas, Mercedes de la Paz, Fiz F. Perez, Gabriel Navarro and Susana Flecha 2019. Methane emissions from the salt marshes of Doñana wetlands: spatio‐temporal variability and controlling factors. Frontiers in Ecology and Evolution, section Conservation.
description: This dataset is subject to a Creative Commons License Attribution‐ShareAlike 4.0 International.
description: [General Notes] The data are provided under an Attribution‐ShareAlike 4.0 International license. However, if you use thedata, so as to support the authors, please consider citing the above mentioned article where data collection and analytical techniques are given in detail. Here we only give a brief details and a guide to the contents of the data files. Data files are in UTF8 encoding, plain text format with {space} used as the delimiter and text enclosed in "". All data files have column titles as the first line. NA is used to represent no data.
description: [Geographical coordinates of water sampling sites] Doñana_saltmarshes_sampling_stations_geo_coordinates.csv provides the geographical coordinates of the sites. ST.ID represents the code (used to link to other data tables) for each site. long and lat are longitude and latitude, respectively. Geographic projection and WSG84 datum is used (EPSG:4326).
description: [Water physiochemical properties] Doñana_saltmarshes_water_monitoring_2016‐2018.csv provides data from approximately monthly water sampling data between March 2016 and March 2018. Temperature, salinity and pH were measured with a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA). Total alkalinity, concentrations of oxygen, organic carbon, organic nitrogen, inorganic nitrogen, pigments, suspended solids and dissolved phosphate were measured in the laboratory. pCO2 was calculated using pH and total alkalinity with co2sys.xls. SAMP.EVENT is a convenience code used to denominate each individual survey. SAMP.DATE is the day in which the sampling took place (in the Gregorian calendar). time.stamp.gmt is the time (GMT or UTC) at which the sample was collected, in extended ISO8601 format. ST.ID represents the code (used to link to other data tables) for each site. T.degC is the water temperature in degrees Celsius. Salinity is the water salinity (practical salinity units, i.e., no units), calculated from conductivity. CH4.nmolL is methane concentration with units nano mol per liter. Chla.μmolL is chlorophyll‐a concentration with units micro mol per liter. TSM.mgL is total suspended solids concentration with units milli gram per liter. DOC.mgL is total dissolved organic carbon concentration with units milli gram per liter. TDN.mgL is total dissolved nitrogen concentration with units milligram per liter. NH4.μmolL is dissolved ammonium concentration with units micro mol per liter. NO2.μmolL is dissolved nitrite concentration with units micro mol per liter. NO3.μmolL is dissolved nitrate concentration with units micro mol per liter. PO4.μmolL is dissolved inorganic phosphate concentration (i.e., not organic or total) with units micro mol per liter. O2.mgL is dissolved oxygen concentration with units mili gram per liter. pCO2.μatm is partial pressure of CO2 in water with units micro atmosphere.
description: [Meteorological data] Daily measurements of air temperature (ºC), wind speed (m s‐1) and humidity were provided by a meteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34” W) maintained by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController). Doñana_saltmarshes_meteorological_data.csv contains monthly‐ensemble‐averaged wind velocities at 1 m (uz) above the land surface with units meters per second. T.degC is monthly mean air temperature at 1m above the land surface with units degrees Celcius. hum.% is the relative humidity at 1m above the land surface expressed as a percent.
description: This data set includes recently published data used to assess the spatio‐temporal variability of dissolved methane in the salt marshes of Doñana National Park, SW Spain (Long:‐6.373, Lat:36.932, Datum:WSG84) between March 2016 and March 2018 and calculate CH4 air‐water fluxes.