Ekologi Suksesi Habitat Orangutan Sumatera di Hutan Dataran Rendah dan Hutan Rawa Gambut

Abstract

Habitat degradation and loss have large and consistent negative effects, not only on the existence of Sumatran orangutans but also, in a larger scope, on the loss of its biodiversity, both flora and fauna as well as ecosystem functions. Flora and fauna are consequently affected by odious forest degradation. The ecosystem restoration program, which most people know it as restoration, is one of the programs conducted to restore damaged forests, both in conservation forests and other types of forests. One of the activities in restoration work is natural succession. The aim of this study is to analyze the composition of species that renders the succession, types of Sumatran orangutan feed, the density of Sumatran orangutans, and the tree phenology in two different forest ecosystems, namely the peat-swamp forest of Rawa Singkil Wildlife Reserve (RSWR) and the lowland forest of Gunung Leuser National Park (GLNP). This study took place on the restoration sites and the reference ecosystems in both of the peat-swamp forest ecosystems and the lowland forest ecosystems. The methods employed in this study were the grid-line method (used for vegetation analysis), the line-transect and direct observation methods (used to form the estimation of Sumatran orangutan population density), and tree phenology. The study was conducted for 14 months. The results of the study showed that Macaranga hypoleuca was the dominant tree species on the peatswamp restoration site of RSWR, whereas Syzygium muelleri dominated in the reference ecosystem of RSWR restoration site. Ficus fistulosa and Macaranga tanarius were the dominant species on the restoration site of lowland forest in GLNP and whereas Shorea leprosula was the dominant tree species in the reference ecosystems of the restoration site of lowland forest in GLNP. The analysis of Sumatran orangutan feed on the restoration site of RSWR showed that 72% of trees on both the restoration site and the reference ecosystems were Sumatran orangutan feed. Subsequently, in lowland forest of GLNP showed that 66% of trees on the restoration site and 79% of trees in the reference ecosystems were recorded as Sumatran orangutan feed. The average estimations of Sumatran orangutan population density on the restoration site of SM. Rawa Singkil were 0.09 ind/km2 and 1.77 ind/km2 in the reference ecosystems. While the average estimations of Sumatran orangutan population density in the GLNP lowland forest were 0.09 ind/km2 on the restoration site and 0.74 ind/km2 in the reference ecosystems.