Estimating of gonystiluss bancanus growing stock in Indonesia (Case study: Riau and Central Kalimantan)

Abstract

Gonystylus bancanus is protected species because it is included in list of critically endangered plant species that is heading to be extinct. Export banned Gonystylus bancanus log trigger illegal logging caused ramin's demand is high. This study aimed to estimate Gonystylus bancanus growing stock in Indonesia. Time series of satellite image was used to identify land use change. Spatial analysis by overlaying of land cover and peatland map found the potential habitat of Gonystylus bancanus. Cluster sampling method was applied to predict growing stock recently year. The study found that growing stock in peat swamp forest in Central Kalimantan (Sebangau National Park area) tend to be elevated. It is also occurred in production forest of peat swamp that is harvested, especially in concession area of Diamond Raya Timber Ltd that also tend to elevate. The most increasing of growing stock is caused by ingrowth). Growing of Gonystylus bancanus seedling is hardly occurred. It is caused by youngest seedling characteristics that are need a covering. Gonystylus bancanus (growing stock is not be spread evenly overall growing stages. This study also found that Gonystylus bancanus growing stock ranging between 4.2 m3/ha to 15.2 m3/ha. The growing stock of Gonystylus bancanus is between 3.3% to 5.4% of all species in peat swamp forest. Average of Gonystylus bancanus increment about 0.63 m3/ha/year. Average growing stock of all species is 3.1 ∼ 20.5 m3/ha/year).