The Orangutan Habitat in Sebangau National Park, Indonesia: Twenty Years of Forest Regrowth

Forest logging operations have negatively affected the populations of orangutans and other wildlife species in Sebangau National Park, Indonesia. Understanding these changes is critical for effective conservation efforts. While techniques for mapping vegetation at landscape scale have advanced significantly, detailed assessments of forest profiles and orangutan habitats at local scale are lacking. To address this gap, data were collected from four forest zones with distinct tree composition, located in two different areas: the Natural Laboratory Peat Swamp Forest (NLPSF) and Punggualas (PA). Sixteen 20 m × 20 m plots were used to collect data on vegetation, soil and water quality, and to construct tree species profiles using the Oldeman method. Physico-chemical factors were measured on-site and laboratory analyses of soil samples were carried out. Canonical correspondence analysis was employed to examine site – species relationships in three dimensions. The analysis revealed that forest regrowth is in progress at both the NLPSF and PA, with significant potential for replacement of the previously logged trees by saplings. Continuous habitat restoration is essential to foster the natural regeneration of tree seedlings that will contribute to future forest recovery. The study also identified spatial heterogeneity in the NLPSF and PA forest habitats, reflecting the disturbed forest structure and the responses of trees to altered patterns of light intensity and water table depth. Nonetheless, the combination of tree species at both locations provided abundant dietary resources for orangutans. Ongoing efforts to enhance recovery of the Sebangau forest ecosystem, involving community participation, have further supported orangutan habitat conservation.