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DOI for Scientific and Technical Data
10.4228/ZALF.2014.324
Title
Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?
Citation
Huth, Vytas; Vaidya, Shrijana; Hoffmann, Mathias; Jurisch, Nicole; Günther, Anke; Gundlach, Laura; Hagemann, Ulrike; Elsgaard, Lars; Augustin, Jürgen (2017): Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?, Leibniz Centre for Agricultural Landscape Research(ZALF)[doi: 10.4228/ZALF.2014.324]
Publisher
Leibniz Centre for Agricultural Landscape Research (ZALF)
Dates
Accepted: 2017
Collected: 2013-11-26/2014-11-04
Contributor(s)
HostingInstitution: Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg (Germany)
RegistrationAgency: German National Library of Science and Technology - TIB
DataCollector: Institute of Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF)
Creator(s)
Huth, Vytas
Vaidya, Shrijana
Hoffmann, Mathias
Jurisch, Nicole
Günther, Anke
Gundlach, Laura
Hagemann, Ulrike
Elsgaard, Lars
Augustin, Jürgen
Subject(s)
Non-steady-state chambers
Net ecosystem exchange (NEE)
Gross primary productivity (GPP)
Ecosystem respiration (Reco)
Grassland
Carbon dioxide
Description
Manual closed-chamber measurements are commonly used to quantify annual net CO2 ecosystem exchange (NEE) in a wide range of terrestrial ecosystems. However, differences in both the acquisition and gap filling of manual closed-chamber data are large in the existing literature, complicating inter-study comparisons and meta analyses. This data set contains data of a study which compares common approaches for quantifying CO2 exchange at three methodological levels. (i) The first level included two different CO2 flux measurement methods: one via measurements during mid-day applying net coverages (mid-day approach) and one via measurements from sunrise to noon (sunrise approach) to capture a span of light conditions for measurements of NEE with transparent chambers. (ii) The second level included three different methods of pooling measured ecosystem respiration (RECO) fluxes for empirical modeling of RECO: campaign-wise (single-measurement-day RECO models), season-wise (one RECO model for the entire study period), and cluster-wise (two RECO models representing a low and a high vegetation status). (iii) The third level included two different methods of deriving fluxes of gross primary production (GPP): by subtracting either proximately measured RECO fluxes (direct GPP modeling) or empirically modeled RECO fluxes from measured NEE fluxes (indirect GPP modeling). Measurements were made during 2013-2014 in a lucerne-clover-grass field in NE Germany. Besides modelled half-hourly RECO, NEE and GPP, measured CO2-fluxes, plant height and C content of aboveground biomass as well as weather conditions are given.
Language
English
Related Datasets
IsDocumentedBy: Publication in JPNSS
Location
Müncheberg
Data Format
csv
Type of Resource
Dataset: Tables
Rights
Creative Commons Attribution-NonCommercial 4.0
Parameter
(parameter; compartment; instrument; method)
PAR (µmol m-2 s-1); half-hourly mean; Sky (Typ SKP215) Quantum Sensor; radiation sensor
Air temperature (°C); half-hourly mean; automatic weather station (LAMBRECHT); RC oscillator + reference capacitors
Soil temperature (2 cm; °C); automatic weather station (LAMBRECHT); RC oscillator + reference capacitors
Soil temperature (5 cm; °C); automatic weather station (LAMBRECHT); RC oscillator + reference capacitors
Soil temperature (10 cm; °C); automatic weather station (LAMBRECHT); RC oscillator + reference capacitors
Air temperature (inside chamber; °C); dimean during chamber measurement; RC oscillator + reference capacitors
Air temperature (outside chamber; °C); mean during chamber measurement; RC oscillator + reference capacitors
Soil temperature (2 cm; °C); during chamber measurement; probe thermometer; RC oscillator + reference capacitors
Soil temperature (5 cm; °C); during chamber measurement; probe thermometer; RC oscillator + reference capacitors
Soil temperature (10 cm; °C); during chamber measurement; probe thermometer; RC oscillator + reference capacitors
Plant height (cm); Plants; folding rule; manually measured
Carbon content (g C m-2) Plants; elemental analyser (CNS 2000); elemental analyses of total carbon content
Measured Reco and NEE-flux (µmol CO2-C m-2 s-1); Inside chamber; LI-820 and LI-840, LI-COR; Infrared gas analyser (IRGA)
Calculated GPP-flux (µmol CO2-C m-2 s-1); NEE-flux - Reco-flux; calculation
Flux of ecosystem respiration (Reco) (g CO2-C m-2 h-1/2); CO2 (half-hourly sum); Empirical model
Flux of gross primary productivity (GPP) (g CO2-C m-2 h-1/2); CO2 (half-hourly sum); Empirical model
Flux of net ecosystem exchange (NEE) (g CO2-C m-2 h-1/2); CO2 (half-hourly sum); Empirical model
Structure of Data Table(s)

Table 1.: Weather_data

Column name Parameter Unit Description
Date_Time  Date and time, format: "DD-MM-YYYY HH:MM"

PAR

Photosynthetic active radiation (µmol m-2 s-1) µmol m-2 s-1 Mean half-hourly photosynthetic active radiation (µmol m-2 s-1)

Air_temp

Air temperature (°C) °C Mean half-hourly air temperature (°C)

Soil_temp_2cm

Soil temperature in 2 cm soil depth (°C) °C Mean half-hourly soil temperature in 2 cm soil depth (°C)

Soil_temp_5cm

Soil temperature in 5 cm soil depth (°C) °C Mean half-hourly soil temperature in 5 cm soil depth (°C)

Soil_temp_10cm

Soil temperature in 10 cm soil depth (°C) °C Mean half-hourly soil temperature in 10 cm soil depth (°C)

 

Table 2.: Plant height

Column name Parameter Unit Description
Date_   Date, format: DD-MM-YYYY

Site_PLot

  Measured site and plot (V4-1 to V4-6))

First_ ... Tenth_plant_height

Plant height (cm) cm Measured plant height (10 repetitions)

Mean

Mean plant height cm Mean value of measured plant height

Median

Median plant height cm Median value of measured plant height

SD

Standard deviation plant height cm Standard deviation of measured plant height

 

Table 3.: NPPshoot

Column name Parameter Unit Description
Date_   Date, format: DD-MM-YYYY

Number_sample

  Site and plot of conducted harvest

Number_laboratory

  Identification number for laboratory use only

Weight_all_kg

Weight of harvested fresh biomass kg Measured weight of harvested fresh biomass

Weight_sample_g

Weight of sampled fresh biomass g Measured weight of sampled fresh biomass

Dry_weight_sample_g

weight of dried biomass sample g Measured weight of dried biomass sample

Dry_matter_percent

Dry matter content (%) % Calculated dry matter content of biomass sample (%)

Dry_matter_all_g

Harvested dry matter (g) g Calculated harvested dry matter (g)

Percent_Ct

C content of dry matter biomass sample (%) % C content of dry matter sample (%)

g_C_sqr_m

C content of dry matter of harvested biomass g C m-2 C content of dry matter of harvested biomass

 

Table 4.: Measured CO2

Column name Parameter Unit Description
Date_Time  ​Date and time, format: "DD-MM-YYYY HH:MM:SS"

Measured_Reco_NEE

CO2-flux (NEE; Reco; µmol m-2 s-1) µmol m-2 s-1) Measured Reco or NEE flux (according to "Chamber_type") in µmol m-2 s-1)

Calculated_GPP_flux

CO2-flux (GPP; µmol m-2 s-1) µmol m-2 s-1 Calculated GPP flux ("indirect" vs. "direct") in µmol m-2 s-1)

Slope_linear_regression

Slope of linear regression - Slope of linear regression between measurement time (t) and CO2 concentration development (ppm) inside chamber during measurement time (t)

Temperature_IN

Air temperature (°C) inside chamber °C ​Mean air temperature inside chamber during measurement time (°C)

R_square_flux

R2 der of linear regression - R2 of the linear regression between measurement time (t) and CO2 concentration development (ppm)inside chamber during measurment time (t)

Temperature_variation

maximum air temperature change (range) during measurment (°C) ​°C maximum air temperature change (range) during measurment (°C)

PAR_variation

maximum PAR change (range) during measurment (%) % maximum PAR change (range) during measurment (%)

FLUX_start_concentration

Athmospherical CO2 concentration % Initial athmospherical CO2 concentration (ppm)

Chamber_type

  Used chamber type(0=opaque;1=transparent (86%))

ID

  Identification number of the measurement

START_rwo

  First row number (within the raw file of IRGA-measurements per ID) of the identified flux

END_row

  Last row number (within the raw file of IRGA-measurements per ID) of the identified flux

P_value_slope

​p-value of the slope of linear regression - Cp-value of the slope of the linear regression between measurement time (t) and CO2 concentration development (ppm) inside chamber during measurement time (t)

Mean_PAR

PAR (µmol m-2 s-1) µmol m-2 s-1 Mean photosynthetic active radiation during measurement time (t)

Mean_soil_temperatur_2cm

Soil temperature in 2 cm soil depth °C Mean soil temperature in 2 cm soil depth during measurement time (°C)

Mean_soil_temperatur_5cm

Soil temperature in 5 cm soil depth °C ​Mean soil temperature in 5 cm soil depth during measurement time (°C)

Air temperature (°C) outside chamber

​Air temperature (°C) outside chamber °C Mean air temperature outside the chamber during measurement time (°C)

Actual_length_measurement

  Length of identified flux in terms of IRGA-records (Frequency=3sec)

Minimal_length_measurement

  Shortest length of identified flux in terms of IRGA-records during one campaign (Frequency=3sec)

Measurement_round

  Measurement round (1 round equals one measurement per frame (6) and shading level (0%-100%))

Measurement_design

  Measurement and modelling design (direct vs. indirect; sunrise vs. mid-day; campaign vs. season)

 

Table 5.: Modelled CO2

Column name Parameter Unit Description
Date_Time  ​Date and time, format: "DD-MM-YYYY HH:MM:SS"

BEST_FIT_INT_REV_UP

  Best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the next campaign

BEST_FIT_INT_REV_DOWN

  Best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the previous campaign

RREF_ ... OUT/IN/2cm/5cm ... _INT_REV_UP

  Rref-parameter of the best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the next campaign

RREF_ ... OUT/IN/2cm/5cm ... _INT_REV_DOWN

  Rref-parameter of the best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the previous campaign

EO_ ... OUT/IN/2cm/5cm ... _INT_REV_UP

  E0-parameter of the best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the next campaign

EO_ ... OUT/IN/2cm/5cm ... _INT_REV_DOWN

  E0-parameter of the best-fit temperature for Reco modelling("IN"; "OUT"; "2cm"; "5cm") of the previous campaign

​FLUX_AVG_INT_REV_UP

​CO2-flux (Reco;µmol m-2 s-1) µmol m-2 s-1 ​Mean Reco flux of the next camapign

FLUX_AVG_INT_REV_DOWN

​CO2-flux (Reco; µmol m-2 s-1) µmol m-2 s-1 ​Mean Reco flux of the previous camapign

A_GPP_INT_REV_UP

  alpha-parameter of the next camapign of PAR fitted against GPP fluxes to model GPP

A_GPP_INT_REV_DOWN

  alpha-parameter of the previous camapign of PAR fitted against GPP fluxes to model GPP

GPMAX_INT_REV_UP

  GPmax-parameter of the next camapign of PAR fitted against GPP fluxes to model GPP

GPMAX_INT_REV_DOWN

  GPmax-parameter of the previous camapign of PAR fitted against GPP fluxes to model GPP

Reco

​CO2-flux (Reco; µmol m-2 h-1/2)

µmol m-2 h-1/2

Modelled Reco flux

NEE

​CO2-flux (NEE; µmol m-2 h-1/2)

µmol m-2 h-1/2

Modelled NEE flux

GPP

​CO2-flux (GPP; µmol m-2 h-1/2)

µmol m-2 h-1/2

Modelled GPP flux

MODEL_MEASUREMENT_TYPE ​

  Measurement and modelling design (direct vs. indirect; sunrise vs. mid-day; campaign vs. season)

 

Additional Information for Dataset
​Refer to the related publication for more details on methods.
View Sample Data
Table 1 (Weather_data) and Table 2 (Plant_height) and Table 3 (NPPshoot) and Table 4 (Measured_CO2) and Table 5 (Modelled_CO2)
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This data by ZALF is licensed under the Creative Commons Attribution-NonCommercial 4.0Creative Commons License