DOI: 10.5281/zenodo.14408901
title: MLA-01 vertical and diurnal stem respiration campaign

description: Description

  
Stem CO2 efflux, or stem respiration, measured vertically and diurnally within MLA-01 / Car-Bel, which is one of the SAFE Intensive Carbon Plots, part of the Global Ecosystem Monitoring (GEM) network, see http://gem.tropicalforests.ox.ac.uk/ located within Maliau Basin Conservation Area. Stem respiration was measured on 13 trees vertically and 18 trees diurnally during May 2023. The stem respiration data collected for this campaign can be linked to other data (census, species, traits) collected from the same stems by the stem tag number. For vertical measurements, stem respiration was measured by tree climbers using the static chamber technique. A 10 cm PVC collar with a 10.6 cm internal diameter was attached to the tree using ratchet straps and hose clips, and modelling clay was used to create an airtight seal around the collar. Stem respiration is then measured with an EGM-4 infrared CO2 gas analyser and SRC-1 respiration chamber (PP Systems) to the collar. Prior to commencing each measurement, the chamber was flushed, and collar fanned to remove stagnant air and the collar was checked for leakage. The chamber is then placed onto the collar and CO2 efflux is measured for 120 seconds. Over the 120 seconds, CO2 accumulates in the chamber and the uncorrected CO2 flux (ppm s-1) is calculated by the IRGA by fitting a linear regression between CO2 concentration and time (mean R2 = 0.954). Flux is calculated from the linear change in concentration in the chamber headspace, and corrected for collar height and air temperature, using the constants:0.106 = Collar diameter, m0.008824734 = Collar area, m2 0.10 = Collar height, m 0.0012287 = Chamber volume, incl. top part of the adapter (as in GEM manual) 0.000441237 = Extra airspace of the collar, m3 0.00211124 = Total chamber headspace, m3 101,325 = pressure 8.314472 = R (gas constant)273.15 = Temperature to Kelvins 12.01 = Molar mass of carbon pV=nRT ideal gas law n=pV/(RT) n=m/M mass mole m=n*M m=MpV/(RT)For diurnal champaign, measurements were conducted over 48-hours per group, except for group A, which was measured for 72-hours. On each sampled stem, a 7 cm PVC collar with a 10.6 cm internal diameter was installed at 1.1 m height with silicone sealant. EA was measured every hour using a LiCOR Li8100A infrared gas analyser and LiCOR Li8150 multiplexer with 15 m extension cables, powered by a 100-ah car battery. The equipment was configured to operate as a closed, self-flushing multiplexed system. To create a closed system, plastic caps with a 11 cm diameter, fitted with in and out push fittings, were secured to the plastic collars, and connected to the LiCOR system using 15 m extension cables. Each measurement duration was 3-minutes, with 90-second dead band and flushed with ambient air between observations. Over the 3-minute interval, CO2 accumulates inside the system and the CO2 flux is calculated as the linear change in CO2 concentration within SoilFluxPro. During the diurnal campaign, temperature and humidity were measured continuously using Tinytag data loggers (TGP-4500; Gemini).

  
  
  
Projects
  

    This dataset was collected as part of the following projects:
  

    
    
https://safeproject.net/projects/project_view/230
    
    
  
  

  

  
  
  
Funding
  

    These data were collected as part of research funded by:
  
  

    
    
Central England NERC Training Alliance (PhD Studentship , NE/S007350/1
      )
    
    
  
  

  
This dataset is released under the CC-BY 4.0 licence, requiring that you cite the dataset in any outputs, but has
    the additional condition that you acknowledge the contribution of these funders in any
    outputs.
  

  
  
  
Permits

  
These data were collected under permit from the following authorities:

  

    
    
Sabah Biodiversity Centre (SABC) ( Research licence JKM/MBS.1000-2/2 JLD.16 (4))
    
  
  

  

  
  
Files

  
This dataset consists of 1 file:
    MLA-01_StemResp_Vertical_Diurnal.xlsx

  
  
MLA-01_StemResp_Vertical_Diurnal.xlsx

  
  
This file contains dataset metadata and 4 data tables:
  
  
Tree_Data
  

    
Worksheet: Tree_Data
    
Description: Description of trees used in the campaign
    
Number of fields: 10
    
Number of data rows: 28
    

      
      
SAFEPlotName: SAFE plot name, as in the SAFE Gazetteer (type: location)
      
      
Subplot: Subplot tree is located in (type: id)
      
      
StemTagNumber: Stem tag number (ID), unique within plot (type: id)
      
      
Census_Date: Census Date (type: date)
      
      
Species: Tree species (as Genus species) (type: taxa)
      
      
Height_m_2016: Tree height, measured with laser hypsometer in 2016 (type: numeric)
      
      
H.POM_m: Heigth of the diameter measurement (default is 1.3 m), or if the tree has a buttress, 50 cm above the top of the buttress (type: numeric)
      
      
D.POM_cm_c2: Diameter at the measurement point (type: numeric)
      
      
Campaign: If the tree was used for the diurnal or vertical campaign, or both (type: comments)
      
      
SpeciesIDsource: Inforomation regarding who collected and who ID'd the specimens (type: comments)
      
    
  
  
  
Climate
  

    
Worksheet: Climate
    
Description: Temperature and relative humidity data during the study
    
Number of fields: 5
    
Number of data rows: 1044
    

      
      
SAFEPlotName: SAFE plot name, as in the SAFE Gazetteer (type: location)
      
      
DateTime: Date and time of measurements (type: datetime)
      
      
TinyTag_Device: TinyTag device used for each recordering (either 2 or 9). Devices were moved to new groups along with the diurnal flux system set up. Tags were connected to trees at breast height with string (type: id)
      
      
Temperature: Temperature as measured by the Tinytag data loggers (TGP-4500; Gemini) (type: numeric)
      
      
Humidity: Relative humidity as measured by the Tinytag data loggers (TGP-4500; Gemini) (type: numeric)
      
    
  
  
  
Diurnal
  

    
Worksheet: Diurnal
    
Description: Data from diurnal campaign
    
Number of fields: 11
    
Number of data rows: 758
    

      
      
SAFEPlotName: SAFE plot name, as in the SAFE Gazetteer (type: location)
      
      
DateTime: Date and time of measurements (type: datetime)
      
      
Date: Date of measurement (type: date)
      
      
Time: Time of measurement (type: time)
      
      
Subplot: Subplot tree is located in (type: id)
      
      
Group: Measurement group (type: id)
      
      
StemTagNumber: Stem tag number (ID), unique within plot (type: id)
      
      
OBS_NUM: Observation number from the LI-8100A recorded in the raw file (type: id)
      
      
PORT: Port that the tree chamber was connected to, ports 1, 3, 7, 9, 11 were used (type: id)
      
      
FCO2_DRY.LIN: CO2 flux recorded from the LI-8100A from a linear fit (type: numeric)
      
      
FCO2_DRY.LIN_SE: Standard error of the flux (type: numeric)
      
    
  
  
  
Vertical
  

    
Worksheet: Vertical
    
Description: Data from vertical campaign
    
Number of fields: 12
    
Number of data rows: 68
    

      
      
SAFEPlotName: SAFE plot name, as in the SAFE Gazetteer (type: location)
      
      
StemTagNumber: Stem tag number (ID), unique within plot (type: id)
      
      
Measurement_Height: Height measurements were conducted at, measured using a Nikon Forestry Pro and confirmed with visual inspection (type: numeric)
      
      
Date: Date of measurement (type: date)
      
      
Time: Time of measurement (type: time)
      
      
EGM_RecordNumber: EGM record number in raw flux file (type: id)
      
      
Slope: Slope of the linear regression between time (seconds) from the chamber closure and CO2 concentration (parts per million, ppm) in the chamber headspace. (type: numeric)
      
      
Diameter_at_MeasurementPoint: Diameter measured at the highest and lowest measurement on each tree (type: numeric)
      
      
AirTemp: Air temperature (type: numeric)
      
      
Measurement_position: Point on the tree measurements were taken, either Buttress, Stem, Above_Branch (type: comments)
      
      
Flux_mg_C_m2ofStemArea_hour: Flux corverted from ppm s-1 to mg (milligrams) carbon per hectare per hour. See conversion below. (type: numeric)
      
      
Q10_Flux_mg_C_m2ofStemArea_hour: Flux_mg_C_m2ofStemArea_hour corrected to 25°C assuming a Q10 of 2.0 : Cavaleri, M.A., Oberbauer, S.F. and Ryan, M.G., 2006. Wood CO2 efflux in a primary tropical rain forest. Global Change Biology, 12(12), pp.2442-2458. (type: numeric)
      
    
  
  
  

  
  

  
  
Extents
  

    
Date range: 2023-05-01 to 2023-06-01
    
Latitudinal extent: 4.747° to 4.748°
    
Longitudinal extent: 116.969° to 116.971°
  

  
  
  
Taxonomic coverage

  
This dataset contains data associated with taxa and these have been validated
    against appropriate taxonomic authority databases.
  
  
  
GBIF taxa details

  
The following taxa were validated against the GBIF backbone dataset (version 2023-08-28). If a dataset uses a synonym, the accepted usage is shown followed
    by the dataset usage in brackets. Taxa that cannot be validated, including new species
    and other unknown taxa, morphospecies, functional groups and taxonomic levels not used
    in the GBIF backbone are shown in square brackets.
  
  
 - Plantae -  - Tracheophyta -  -  - Magnoliopsida -  -  -  - Ericales -  -  -  -  - Sapotaceae -  -  -  -  -  - Payena -  -  -  -  -  -  - Payena microphylla -  -  -  - Fabales -  -  -  -  - Fabaceae -  -  -  -  -  - Dialium -  -  -  -  -  -  - Dialium indum -  -  -  - Fagales -  -  -  -  - Fagaceae -  -  -  -  -  - Lithocarpus -  -  -  -  -  -  - Lithocarpus urceolaris -  -  -  - Laurales -  -  -  -  - Lauraceae -  -  -  -  -  - Eusideroxylon -  -  -  -  -  -  - Eusideroxylon zwageri -  -  -  - Malpighiales -  -  -  -  - Achariaceae -  -  -  -  -  - Ryparosa -  -  -  -  -  -  - Ryparosa acuminata -  -  -  -  - Euphorbiaceae -  -  -  -  -  - Mallotus -  -  -  -  -  -  - Mallotus wrayi -  -  -  -  - Irvingiaceae -  -  -  -  -  - Irvingia -  -  -  -  -  -  - Irvingia malayana -  -  -  -  - Phyllanthaceae -  -  -  -  -  - Aporosa -  -  -  -  -  -  - Aporosa falcifera -  -  -  - Malvales -  -  -  -  - Dipterocarpaceae -  -  -  -  -  - Dryobalanops -  -  -  -  -  -  - Dryobalanops lanceolata -  -  -  -  -  - Hopea -  -  -  -  -  -  - Hopea sangal -  -  -  -  -  - Parashorea -  -  -  -  -  -  - Parashorea malaanonan -  -  -  -  -  - Richetia -  -  -  -  -  -  - Richetia faguetiana -  -  -  -  -  -  - Richetia gibbosa -  -  -  -  -  - Rubroshorea -  -  -  -  -  -  - Rubroshorea beccariana -  -  -  -  -  -  - Rubroshorea dasyphylla -  -  -  -  -  -  - Rubroshorea parvifolia -  -  -  -  -  - Shorea -  -  -  -  - Malvaceae -  -  -  -  -  - Scaphium -  -  -  -  -  -  - Scaphium macropodum -  -  -  - Myrtales -  -  -  -  - Myrtaceae -  -  -  -  -  - Syzygium -  -  -  -  -  -  - Syzygium leucocladum -  -  -  - Sapindales -  -  -  -  - Burseraceae -  -  -  -  -  - Canarium -  -  -  -  -  -  - Canarium decumanum