Difficulties Encountered in Estimating Soil Emissions due to

Difficulties Encountered in Estimating Soil Emissions due to LUCF Gary W. Theseira Forest Research Institute Malaysia Kuala Lumpur, Malaysia

Tropical Soils: • Tropical climates – – High year-round temperatures High rainfall High biomass production High decomposition rates • Tropical soils are: – Highly weathered – Low in organic matter – Not normally considered a significant sink for carbon • There are, however notable exceptions …

Soils with significant Organic Carbon content: • Peat swamps (Histosols) – Accumulation of organic matter under fresh-water swamps or soils with a water table close to the soil surface • Bris Soils (Spodosols) – Accumulation of organic matter due to the presence of a fluctuating water table within a deep, sandy soil • Highland organic soils (Histosols) – Accumulation of organic matter above the soil surface due to low night temperatures that reduce decomposition rates.

Extent of Peat Swamps in Malaysia • Peninsular Malaysia • Sarawak • Sabah 793, 000 ha 1, 466, 000 ha 86, 000 ha • Total of ca. 2. 5 million ha • Comprise 7% of the total land area

Properties of Peat Swamps in Malaysia • Developed during comparatively recent times – Carbon dated ca. 5400 y. b. p. • Formed under poorly drained terrestrial conditions rather than a permanent water body • Profile – Upper layer – Middle layer – Bottom layer 20 to 30 cm thick 30 to 40 cm thick variable thickness sapric o. m. hemic o. m. fabric o. m. • Overall depth of the peat may reach 17 m (Anderson, 1983)

Utilization Status of Peat Swamps in Malaysia • Primary use still peat swamp forest • Little more than 10% converted for agriculture, however … • Some located within regional agricultural development schemes – Johor Barat – Endau-Rompin • > 50% of project area located on peat soils • Located primarily in Peninsular Malaysia

Sources of Uncertainty in Utilization Status of Peat Swamps in Malaysia • How do we estimate land area under different and changing use: • Steady-state single-use – Non-utilized – Low-impact use – Intensive use • Land in transition/multiple-use – Gradual change & small land parcels – Catastrophic change • INTENSIVE/EXTENSIVE DRAINAGE • PEAT FIRES • Illegal or unreported land use change negligible emissions or net sink low emissions high emissions

Sources of Uncertainty of Emissions from Peat Swamps • How do we estimate emissions from peat soils associated with: • Logging – Selective logging – Clearcut logging • Agriculture – Subsistence – Commercial vegetable and fruit production – Oil palm production • Other – Fishing – Fish farming – Fuelwood collection

Drainage and Subsidence Measured subsidence data for Sarawak Source Tie and Kueh (1979) Subsidence (cm/year) Initial year 1 and 2 (consolidation) After year 2 (oxidation & shrinkage) 50 6 Yogeswaran (1990) 16 Agric. Research Station Sibu 4. 4 a Salmah (1998) 5 Chin and Poo (1991) 6 – 35 b a. Average subsidence rate over the period 1983 – 2000 b. Higher values in the vicinity of the drains (Source: PS Konsultant and LAWOO, 2001)

Complementary Verification Technologies • Modelling techniques for estimating oxidization rates given different rates of water-table recession • Ground-penetrating radar to estimate water table depth and overall peat thickness • Use GIS/thermal imaging to characterize peat swamps – – Hot Warm Ambient Cool peat fires dry edge peat swamp surface water

Solving Administrative and Communication Issues between Government Ministries • Consolidating Natural Resource and Environmental agencies under a common ministry • Mandate from the Prime Minister to Improve Communication and Strengthen Cooperative Ties between Environmental, Industrial, Technological and Economic Planning ministries

International Cooperation • Easier said than done • Always torn between ‘bottom-up’ and ‘top-down’ • Subject to Bureaucratic Inertia • Optimistic • ‘Small steps & Slow gains’ approach • Persistent