Analysis of land cover changes, genetic structure, and carbon biomass stock of pinus Merkusii Jungh Et De Vriese Strain Tapanuli In Its Natural Distribution In North Sumatra | Analisis perubahan tutupan lahan, struktur genetik dan kandungan biomassa karbon Pinus merkusii Jungh. et de Vriese strain tapanuli pada sebaran alaminya di Sumatera Utara

Pinus merkusii strain Tapanuli is currently considered as endangered because of declining population and habitat due to logging activity and land use changes. With recent development on carbon trade the natural populations of P. merkusii strain Tapanuli has the potential as carbon sink. The objective of the research were 1) To analyze the landcover changes in five locations of strain Tapanuli natural habitat, which occured in 1994, 2005, and 2011, 2) To analyze the genetic structure of those five natural populations using microsatellite markers 3) To formulate the allometric equation for carbon biomass estimation of strain Tapanuli. Five study locations in strain Tapanuli natural habitat were selected as follows: a) two protected forests, i.e. Dolok Tusam Timur and Dolok Tusam Barat, b) two open and cultivated area, i.e. Parinsoran and Lobugala village, and c). Mixed forests in Tolang hilly village. Analysis of land cover changes was based on Landsat imagery 7 ETM+ in 1994, 2005, and 2011. Microsatellite markers were generated from microsatellite primers developed previously on P. merkusii strain Aceh. Formulation of allometric equations was done using destructive sampling method combined with volumetric method. The results showed that 1) Land cover changes that occur in Tapanuli terrestrial ecosystem from 1994 to 2011 has led to increased extent of weeds-shrub land, and cause the site of natural populations of Tapanuli strain of P. merkusii into nutrient poor. The cumulative soil carbon stock in the five research sites are as follows: Dolok Tusam Timur 55,5 ton C/ha, Parinsoran 46,1 ton C/ha, Dolok Tusam Barat 65,8 ton C/ha, Lobugala 89 ton C/ha, dan Tolang 71,1 ton C/ha. 2) Heterozygosity levels of those populations were high, and Population of Parinsoran and Tolang into one group, Population of Lobugala into one grup. 3). The best allometric equation for estimation of biomass carbon content of P. merkusii strain Tapanuli as follows: allometric equation for above ground biomass is Y = 0,1900(DBH)2,2730; for below ground biomass is Y = 0,0283(DBH)2,4393 and allometric equation for total biomass estimation of P. merkusii strain Tapanuli is Y= 0,2451(DBH)2,2757, 3). Based on this equation the potential carbon estimated in five location of natural distribution of P. merkusii strain Tapanuli are as follows: Dolok Tusam Timur 187,8 ton C/ha, Parinsoran 48,9 ton C/ha, Dolok Tusam Barat 190,4 ton C/ha, Lobugala 93,2 ton C/ha, and Tolang 45,7 ton C/ha.