publication . Article . 2017

High heterotrophic CO2 emissions from a Malaysian oil palm plantations during dry-season

Magdalena Matysek; Stephanie Evers; Marshall K. Samuel; Sofie Sjögersten;
Open Access English
  • Published: 01 Dec 2017
  • Publisher: Springer Verlag
  • Country: United Kingdom
Abstract
AbstractTropical peatlands are currently being rapidly cleared and drained for the establishment of oil palm plantations, which threatens their globally significant carbon sequestration capacity. Large-scale land conversion of tropical peatlands is important in the context of greenhouse gas emission factors and sustainable land management. At present, quantification of carbon dioxide losses from tropical peatlands is limited by our understanding of the relative contribution of heterotrophic and autotrophic respiration to net peat surface CO2 emissions. In this study we separated heterotrophic and autotrophic components of peat CO2 losses from two oil palm plantations (one established in ‘2000’ and the other in 1978, then replanted in ‘2006’) using chamber-based emissions sampling along a transect from the rooting to non-rooting zones on a peatland in Selangor, Peninsular Malaysia over the course of 3 months (June–August, 2014). Collar CO2 measurements were compared with soil temperature and moisture at site and also accompanied by depth profiles assessing peat C and bulk density. The soil respiration decreased exponentially with distance from the palm trunks with the sharpest decline found for the plantation with the younger palms with overall fluxes of 1341 and 988 mg CO2 m−2 h−1, respectively, at the 2000 and 2006 plantations, respectively. The mean heterotrophic flux was 909 ± SE 136 and 716 ± SE 201 mg m−2 h−1 at the 2000 and 2006 plantations, respectively. Autotrophic emissions adjacent to the palm trunks were 845 ± SE 135 and 1558 ± SE 341 mg m−2 h−1 at the 2000 and 2006 plantations, respectively. Heterotrophic CO2 flux was positively related to peat soil moisture, but not temperature. Total peat C stocks were 60 kg m−2 (down to 1 m depth) and did not vary among plantations of different ages but SOC concentrations declined significantly with depth at both plantations but the decline was sharper in the second generation 2006 plantation. The CO2 flux values reported in this study suggest a potential for very high carbon (C) loss from drained tropical peats during the dry season. This is particularly concerning given that more intense dry periods related to climate change are predicted for SE Asia. Taken together, this study highlights the need for careful management of tropical peatlands, and the vulnerability of their carbon storage capability under conditions of drainage.
Persistent Identifiers
Fields of Science and Technology classification (FOS)
01 natural sciences, 0105 earth and related environmental sciences, 010504 meteorology & atmospheric sciences, 04 agricultural and veterinary sciences, 0401 agriculture, forestry, and fisheries, 040103 agronomy & agriculture
Subjects
free text keywords: GE, QD, QK, Management, Monitoring, Policy and Law, Aquatic Science, Ecology, Evolution, Behavior and Systematics, Agronomy, Greenhouse gas, Dry season, Carbon dioxide, chemistry.chemical_compound, chemistry, Peat, Context (language use), Environmental science, Carbon sequestration, Soil respiration, Bulk density
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