Daily cycles in soil carbon flux

Description:

Measurements of 24 hour cycles in soil CO2 flux taken from soil collars in the Belian Carbon plot at Maliau. Measurements were taken from 12 subplots over four days at 5-hourly intervals, ensuring good coverage of the complete 24 hour cycle. Air and soil temperatures, soil moisture content and CO2 flux were taken from each plot at each visit. 9 subplots only have a single total soil respiration collar, but 3 subplots also have soil flux partitioning treatments to separate contributions to total respiration from soil organic matter, mycorrhizae and roots.

This data was collected by the 2019 cohort of the Tropical Forest Ecology MRes at Imperial College London.

Project: This dataset was collected as part of the following SAFE research project: MRes Tropical Forest Ecology Field Course

XML metadata: GEMINI compliant metadata for this dataset is available here

Files: This dataset consists of 2 files: Carbon_corrected_slopes.xlsx, raw_egm.zip

Carbon_corrected_slopes.xlsx

This file contains dataset metadata and 2 data tables:

1. 24 hour observations of CO2 flux patterns (described in worksheet Carbon_flux_data)

   Description: Estimated CO2 flux values, soil moisture and air and soil temperatures from Carbon subplots

   Number of fields: 14

   Number of data rows: 296

   Fields:

   • record_no: EGM 'Plot' value - record number on EGM machine for this collar (Field type: ID)
   • plot: Carbon subplot number (Field type: Location)
   • date: Calendar date that measurements taken (Field type: Date)
   • time: Time that measurements taken (Field type: Time)
   • soil_wmc: Soil water moisture content (Field type: Numeric)
   • soil_temp: Soil temperature (Field type: Numeric)
   • air_temp: Air temperature (Field type: Numeric)
   • treatment: Exclusion treatments for partitioning soil respiration components (Field type: Categorical)
   • field_flux: CO2 flux reported in the field by EGM (Field type: Numeric)
   • Source: EGM dat file of source data used for corrected fluxes where available (Field type: File)
   • corrected_flux: Corrected flux measurements using by eye exclusion of raw flux data (Field type: Numeric)
   • n_points: Number of points in EGM record (Field type: Numeric)
   • n_used: Number of points used for corrected slope estimation (Field type: Numeric)
   • flux: Final flux values, using corrected values where available (Field type: Numeric)

2. EGM raw data (described in worksheet EGM_raw_data)

   Description: Duplicates key information from raw EGM files and indicates points excluded in calculation of corrected flux values

   Number of fields: 7

   Number of data rows: 7114

   Fields:

   • Plot: EGM recorder 'plot' code, actually just the record sequence number. (Field type: ID)
   • RecNo: EGM record number - time points of gas measurement at a single plot (Field type: ID)
   • Datetime: Time of gas concentration measurement (Field type: Datetime)
   • CO2.Ref: Measured CO2 (Field type: Numeric)
   • Input.E: EGM internal variable used in slope estimation (Field type: Numeric)
   • Source: Original EGM dat file containing the flux data (Field type: File)
   • ignore: Indicates where points from raw data excluded from corrected slope calculations (Field type: Categorical)

raw_egm.zip

Description: Zipfile of raw EGM dat files

Date range: 2019-02-18 to 2019-02-21

Latitudinal extent: 4.7467 to 4.7480

Longitudinal extent: 116.9693 to 116.9704