The study was conducted in tropical peatlands in the upper catchment of the Sebangau River near Palangkaraya, the capital city of Central Kalimantan province, Indonesia. In Central Kalimantan, a large peatland area was deforested and drained during the late 1990s, mainly to develop farmlands according to a national project: the Mega Rice Project (MRP). The site had been logged selectively until the late 1990s, so that it is an almost secondary forest. However, it was designated a National Park in 2006 and retains a relatively intact forest.Rich shrubbery grows in the understory.,The soil surface was covered with thick tree debris, mainly comprising leaf litter. Few herbaceous plants existed on the soil surface. The forest floor was uneven with hummocks and hollows. Hummocks, which are formed on dense tree roots, are surrounded by hollows.Hummocks, which are formed on dense tree roots, are surrounded by hollows. Hollows are networks of open soil surfaces between hummocks. Hummock surfaces are typically 20–30 cm higher than hollow surfaces. The peat depth was 2–3 m. A 35m high tower was built in 2004 for flux measurement. Fetch for the flux measurement was longer than 1 km in all directions.The turbulent fluxes of sensible heat, latent heat, CO2 were measured using the eddy covariance system.
