In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

265and Kerinci populations were 0.219 and 0.042, respectively (Na’iem & Munawar2001, pers. comm.). Tapanuli and particularly Kerinci populations are relativelysmall and scattered and consequently, the inbreeding rate is expected to behigh which gives rise to low genetic variation.Threats to the Natural Populations of Pinus merkusiiAmong three natural populations of P. merkusii in Sumatra, the Aceh populationis the largest in terms of size. The population is divided further into three disjunctsubpopulations, namely Jantho, Takengon and Blangkejeren. At the end of the1960s, the Aceh population occupied around 200 000 ha (Cooling 1968); however,its size is steadily declining due to logging and conversion of its habitat intoagricultural land. Since 1989 the subpopulation of Takengon has been logged tosupply wood fiber for a kraft paper mill nearby and many stands in thissubpopulation have been cleared. The threat to this population comes also fromgenetic contamination, in which some of the logged-over areas are planted notusing available genetic materials from the local seed source, but seed importedfrom Java.Realizing the serious threat to the subpopulation of Takengon, an effortis being made to conserve some of the populations in this area. In this program,13 stands varying from 20 to 425 ha in size were designated as conservationstands. The stands were selected based upon stand condition, representativenature of the site, and accessibility. Details of the in situ conservation of P.merkusii in Aceh were previously described by Hardiyanto (1993).P. merkusii in Aceh is most prominent at elevations from 500 to 1700m. However, many stands of the subpopulation of Jantho are found at lowerelevations (200 - 300 m) and considered as outliers. It is fortunate that thesubpopulation is still in good condition due to its poor accessibility. Illegal cuttingis only minor there.Despite the absence of extensive logging operations in the Blangkejerensubpopulation, this subpopulation has long been suffering from geneticimpoverishment due to the practice of negative selection. Local people haveselectively felled the best trees in the stand and left the poor ones (Hardiyanto1993).P. merkusii in Tapanuli occurs at an elevation of around 950 m and it isfragmented into a number of subpopulations. Previously, the extent of theTapanuli population was estimated to be around 3500 ha (Hardiyanto 1993) butits size has been steadily declining in recent years, mainly due to logging. It istrue that many logging activities have occurred in the stands growing on thelocal community land, but illegal logging has also taken place in the state forest