POTENTIAL CARBON SEQUESTRATION BY REHABILITATION OF DEGRADED PEAT SWAMP FORESTS IN GIAM SIAK KECIL-BUKIT BATU BIOSPHERE RESERVE, RIAU, INDONESIA

Abstract

Rehabilitation commenced in February 2010 in Giam Siak Kecil-Bukit Batu Biosphere Reserve which covers a total area of 698,663 ha. This paper highlighted research progress on rehabilitation of degraded logged over peat swamp forests, and estimation amount of sequestered carbon after ten months vegetation rehabilitation was done. Line and gap planting methods were applied. The following lands of planting were applied normal and hill planting methods. For monitoring biomass and carbon five plots of 10x10m were selected. Tree species with DBH>3cm were identified and recorded. We used diameter increment of species planted to estimate increment of biomass, carbon storage and carbon sequestration. The allometric equation was used: Y=-2.13+2.53*ln DBH; where Y is total above-ground biomass in Kg/Mg ha-1 and DBH is in cm. The carbon content was calculated by multiplying the 0.5 conversion factor to the above ground biomass. The results indicate that some species of Cratoxylon arborescens, Palaquium sumatranum, Palaquium burckii, and Tetramerista glabra were promising species for rehabilitating degraded peat swamp forest areas shown by high survival rates in the range of 73.3 to 100%. The greatest growth performance are Cratoxylon arborescens, then followed by Tetramerista glabra. Biomass increased from 2.94 Kg ha1 to 28.9 Kg ha-1, and carbon storage increased from 1.55 Kg C ha-1 to 14.5 Kg C ha-1 with total carbon storage 12.5 Kg C ha-1 in experimental sites. The forest recovery through natural regeneration processes contributed in sequestrating carbon of 0.34 Mg C ha-1 during ten months monitoring. In the say direction, there was an increasing in biomass from 3.88 Mg ha-1 to 4.57 Mg ha-1 and carbon storage of 1.99 Mg C ha-1 to 2.28 Mg C ha-1. The total amount of carbon sequestration was 0.35 Mg C ha-1 in both experimental sites and forested areas. Rehabilitation through planting trees and natural regeneration processes are important in order to restore carbon storage of remaining peat swamp forests in biosphere reserve.