Abstract
Tropical rainforests continue to disappear causing unprecedented losses in biodiversity and ecosystem services. Despite an increasing recognition of the value of these public goods at local, national and global levels, rainforests continue to be seriously threatened by various forms of encroachments such as low-intensity harvesting of non-timber forest products by the rural poor and the conversion of forests e.g. to agroforestry systems or agricultural land. The stability of rainforest margin areas has been identified as a critical factor in the protection of tropical forests. Stability in this context has an ecological, social and economic dimension. Understanding the ecological and socio-economic determinants of land use change in tropical rainforest margins on different spatial scales is the key to identify more suitable development objectives and programs that better combine nature conservation, poverty reduction, and economic development of rural areas (Priess et al. 2006).
In this paper we analyze the role of regional and local institutions namely the National Park Authorities (province level) and the local administration (village level) in their effects on historical and potential future land use change at the forest margin. The study is based on a combination of field research, remote sensing analysis and simulations of land use change employing the SITE model (Priess et al. 2006). Under the umbrella of the collaborative research project „Stability of Rainforest Margins“ (STORMA) Indonesian and German scientists jointly study numerous components of the coupled human-environmental system in the province of Central Sulawesi, Indonesia. The research area covers approximately 7.500 km˛, located south of the provincial capital of Palu. Forests – including the Lore Lindu National Park (LLNP) - are still the dominant land cover, but have been reported to decrease at a rate of 0.6% over the last 30 years (Erasmi et al. 2005). During recent years, an increasing number of cacao plantations are being installed either on agricultural land or on forest land, while the production of the traditional food crop paddy rice is loosing importance (Weber et al. 2006). Forest conversion occurred and still occurs both in LLNP forests and unprotected forests. Many of the villages located at the LLNP-border have been established long before the LLNP, which was and still is associated with legal restrictions of land use for the villagers. In addition to an increasing local population, a considerable number of people immigrated into the research area, due to relatively favorable environmental conditions and the availability of land suitable for agriculture, especially for cacao agroforestry. Access to land, as a prerequisite for agricultural expansion and forest conversion, seems predominantly to be regulated by local authorities at the village level. Agricultural expansion and forest conversion vary widely between different villages, indicating an only partly successful collaboration between regional and local institutions in protecting the LLNP forests (Shohibuddin 2005). In the year 2002, approximately 88% of the LLNP area was covered by primary forests, while 12% were shared by secondary vegetation, agriculture, agro-forestry and a small fraction of settlement area. 2002 also serves as the base year for the land use change scenarios, which are covering the next two decades until the year 2025. We simulated the impact of local and regional institutions on land use change, varying the degree of protection of LLNP forests, comparable to the way fuzzy set approaches translate and quantify linguistic variables. We used the spatially explicit SITE model, which has been developed for regional studies (Mimler and Priess 2006), to simulate the influence of institutions on land use change. We developed scenarios assuming different protection policies (open access, intermediate protection, perfect protection), also reflecting different degrees of collaboration between local and regional institutions. Policy options for example limiting the flow of immigrants, or economic measures, involving other regional or national institutions were not in the focus of this paper. Forest protection was simulated by reducing or increasing the suitability for agriculture of the land pixels within the LLNP, according to the assumed degree of protection. As a result of improved institutional efficiency to protect the LLNP forests, larger areas of unprotected forests were converted in the almost 70 villages adjacent to the national park. Our results suggest that a close collaboration between different regional and local institutions is required to avoid negative impacts of successful forest protection on adjacent forests or elsewhere in the region.
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