Carbon dioxide and energy fluxes above an oil palm canopy in peninsular Malaysia
By: MH Haniff, Anis Ibrahim, Nur Maisarah Jantan, Nuramanina Shahabudin, Hasimah Mos, Yusri Yusup
Key Words: Oil palm, CO2 flux, Energy flux, Eddy covariance.
Int. J. Agr. Agri. Res. 9(2), 137-146, August 2016.
A study was conducted on carbon dioxide (CO2) and energy fluxes (i.e. latent (L) and sensible heat (H)) above the canopy of mature oil palms planted on the inland mineral soil in Keratong, Pahang, Peninsular Malaysia. The measurement was conducted over an 18-month period from September 2013 to August 2014, using the eddy covariance method. There was a significant seasonal variation in the monthly averaged CO2 fluxes over the measurement period. The monthly averaged CO2 flux values ranged between -2 to -6 μmol m–2 s–1, with an average value of about -3.5 μmol CO2 m–2 s–1. This could be due to the irregular cumulative monthly precipitation and net radiation during the observation period. Relatively low average monthly CO2 flux (or high uptake of CO2) also corresponds with the lowest monthly average LE and rainfall in months February 2013 and 2014. The negative CO2 flux value shows that the mature oil palm ecosystem from an inland mineral soil area in Peninsular Malaysia was a sink for CO2. Analysis of energy balance closure shows that the slope between latent and sensible heat fluxes and total incoming energy was about 0.69 with an r2 value of 0.86. The slope value obtained in this study suggests that there was a surplus of available energy compared to the measured energy fluxes. Energy balance ratio was about 0.81 and comparable to other agricultural surfaces. This means that 81% of the available energy was accounted through the surface flux measurements.