Do Microsites within Oil Palm Plantations on Tropical Peatland Reflect CO2 Emission? Marshall Kana Samuel1,2 and Stephanie Evers1 1School of Biosciences, The University of Nottingham Malaysia Campus. 2Climate Change, Adaptation and Mitigation Programme, MARDI.
[email protected]
Background
Figure 1 CO2 Emission from Microsite Between Land Use
mg CO2 m-2 hr-1
• Soil Respiration (SR) is defined as Autotrophic Respiration (AR) + Heterotrophic Respiration (HR). However, estimation of AR/SR% value from oil palm plantations on tropical peatland have a wide range, between 62% - 14%[1,2]. • The existence of micro-topography[3] by management practice is likely to reflect CO2 emission variation. • Hence, this study aims to quantify site-specific CO2 emissions within land uses at varying age classes namely LU1 (15 years), LU2 (9 years) and LU3 (2 years, 2nd generation), as well as to estimate AR/SR% using potential HR from respective microsites within land uses.
Experiment Microsite in Oil Palm Plantation Harvesting Path (HP)
Table 1
Under Canopy (UC)
Land Use Far from Palm (FF)
Frond pile (FP)
Sampling Port
Estimation of AR/SR% Using Respective Microsites as HR
LU1
HP 32
FP 74
FF 83
LU2
22
47
35
LU3 Average
20 25
52 58
51 56
Thermometer
Glass Vials
9V Battery
Results Gas samples were collected using static closed-chamber system (sub-plate) at KLIA Sepang oil palm plantation within microsites during rainy season (November 2015).
Soil sampling at five different depths from 20cm to 100cm. Soil samples were collected using Russian corer (Eijkelkamp Agrisearch Equipment)
• The highest CO2 emission was measured from the oldest converted site, LU1 followed by LU2 and LU3, with the rate of emission 1368.64 ± 257.07, 906.83 ± 64.72 and 739.61 ± 90.81 (mg CO2 m-2 hr-1), respectively (Figure 1). • We estimated AR by subtracting HR candidates from SR and presented in AR/SR% value (Table 1). AR/SR% means variation using HR candidates were ranged 58% - 25% for all land uses, and within reported results [1,2] . • The higher AR/SR% values were estimated at LU1, specifically within the FF (83%) and FP (74%) microsites. This indicates the microsites had lower HR values that reflect undisturbed areas of Imperata sp. and decayed fronds pile.
Conclusion Gas Chromatography (GC) (Agilent 7890A) equipped with Thermal Conductivity Detector (TCD) for CO2 gas analysis.
The significant role from each microsite in AR/SR% estimation is essential to gain more insight on the tropical peat oil palm plantations status, rather than to estimate absolute HR value. This is because the heterogeneity traits within microsite in term of carbon cycle and soil properties could change the HR value that been affected by management practices.
References
R2LU1 (FF) 250
y = 495.93x + 105.08 R² = 0.9969
mg CO2 m-2
200 150 100
Plateau was omitted from calculation
50 0 0
0.05
0.1 Hour (h)
0.15
0.2
Example of CO2 emission rate (slope) calculation using Linear Regression (LR) with minimum three points of time interval.
[1] Dariah, A., Marwanto, S., & Agus, F. (2014). Root- and peat-based CO2 emissions from oil palm plantations. Mitigation and Adaptation Strategies for Global Change, 19(6), 831–843. http://doi.org/10.1007/s11027-013-9515-6 [2] Melling, L., Yun Tan, C. S., Goh, K. J., & Hatano, R. (2013). Soil microbial and root respirations from three ecosystems in tropical peatland of Sarawak, Malaysia. Journal of Oil Palm Research, 25(APR), 44–57. [3] Luskin, M. S., & Potts, M. D. (2011). Microclimate and habitat heterogeneity through the oil palm lifecycle. Basic and Applied Ecology, 12(6), 540–551. http://doi.org/10.1016/j.baae.2011.06.004.
