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

266land, some of which has been designated as conservation areas. Geneticcontamination has also occurred in this population as reforestation often usesseed of P. merkusii imported from Java.Among three populations of P. merkusii in Sumatra, the Kerincipopulation is the most seriously threatened. The population has been severelyfragmented, and some of the stands now occupy an area less than 1 ha andconsist only few trees,which are often mixed with other tree species. P. merkusiiin this population occurs at elevations between 1250 and 1400 m. While onesubpopulation is relatively secure as it grows on the protected area of Kerinci-Seblat National Park, continued tree felling and conversion of the forest intoCinnamomum plantations likely caused some significant loss of valuable genesof this population. As found in Aceh and Tapanuli, genetic contamination hasalso occurred in the Kerinci population.Management of Ex situ ConservationContinuing threats to the natural populations of P. merkusii in Sumatra and theneed to broaden the genetic basis of the current breeding program of this specieshave led to the effort of securing genetic materials from natural populations.For species under intensive domestication and for which breeding programsare in place, such as P. merkusii, conservation efforts are better integratedwith the existing breeding program (Namkoong 1986, Palmberg-Lerche 1999).Seed collection from Aceh was carried out during 1996 and 1997.Since information on the pattern of genetic variation was not available at thistime, the strategy for seed collection was to sample as many subpopulations aspossible. These new genetic materials were then planted as progeny tests ontwo sites in Java (West and East Java) in 1997 and 1998. These breedingpopulations also function as ex situ conservation stands. The infusion of geneticmaterial from the natural population is structured according to a multiplepopulation breeding system (MPBS). In this regard, populations are subdividedinto subpopulations or sublines. MPBS was reported to be very effective inmaintaining genetic diversity in Pinus taeda, and the MPBS aggregate hadgenetic diversity similar to that of natural stands (Williams and Hamrick 1996).The grouping of the newly introduced genetic materials was basedupon the place of origin of seed collection. Table 1 presents the subpopulationsand number of families successfully progeny tested. It is worth noting that theoriginal number of families in the seed collection was larger than those presentedin Table 1. Due to poor viability, not all families were included in the progenytests but the number of families in each subpopulation is considered adequateto maintain the current level of diversity. Taking seeds from at least 15 trees