Prospects of adoption of tree-based systems in a rural landscape and its likely impacts on carbon stocks and farmers' welfare: the fallow model application in Muara Sungkai, Lampung, Sumatra, in a 'clean development mechanism' context

Abstract

Environmental services provided by a landscape, including carbon stocks stored, depend on land use patterns. Adoption of land use practices among choices of land use systems in a rural landscape depends on farmers’ strategic decisions in allocating land and tactical decisions in allocating labour, both likely to be based on the results farmers expect to obtain, and strongly conditioned by capital availability. Their expectations gradually change on the basis of local experience, and are influenced by external information sources (knowledge diffusion from elsewhere and ‘extension’ or the priming of expectations for land use practices that are not yet widespread). At the local community scale, specific restrictions on land use options are set, and issues such as fire control are determined by the cohesiveness of the local community. Prices of the various commodities and their volatility are determined by th e surrounding economy, as does the wa ge rate for off-farm and out-of-the- landscape labour opportunities. The overall outcome of the dynamic land use mosaic determines the amount of biomass and carbon stocks of the landscape. The FALLOW model was designed to provide a comprehensive description of the factors and interactions described above, to allow the testing of hypotheses about ‘causal’ explanations (including the various direct and indirect feedbacks) and to evaluate ‘scenarios’ of ‘baseline’ and policy-change land use evolution. Baselines are important in the discussion of ‘environmental service rewards’, while the likely response to ‘rewards’ can include ‘perverse incentives’ and ‘leakage’, if additional capital relieves constraints to the development of less-environmental friendly land use options. This paper reports results on prospective analyses using the FALLOW model on adoption of land use systems by transmigrant and local farmers in lowland peneplain of Muara Sungkai, Lampung, Sumatra. Specific focus was to compare a 'project' (rapid tree planting in a limited area) approach to a programmatic one (facilitating spontaneous tree adoption in a larger area) in terms of carbon-stocks gains and projected effects on farmers’ welfare, in a 'clean development mechanism' context. The results suggested that a ‘project’ approach was likely able to increase carbon stocks without leakage in a short-term monitoring period. However a reduction of carbon stocks below baseline (‘leakage’) can be expected in the longer term if the tree planting approach did not provide off-farm employment opportunities to surrounding farmers. If co sts of ‘extension’ and ‘social control on fire’ are assumed to be zero, the ‘programmatic’ approach to removing constraints to spontaneous smallholder adoption was likely able to increase both carbon stocks and farmers’ welfare better than the simulated ‘project’ approach