Application of a system dynamics model to evaluate the implementation of payment for environmental services as a reconversion mechanism in high mountain farming

In Colombia, livestock farming has been developed in highlands areas, with influence on these ecosystems and their ecosystem services. Reason why, in 2017, the Colombian issued legal regulations (Decree Law 870), which establishes the payment for environmental services (PES) as a key instrument in the conservation of strategic areas to achieve comprehensive rural development. The objective of this study was to evaluate the response of two type of highlands livestock agroecosystems to the implementation of a mechanism such as the PES, through scenario simulation based on the System Dynamics methodology. It should contribute to the understanding of this activity and to the formulation of policies for land management, use and conservation. Data and information used in this study came from farms located in La Nevera, municipality of Palmira, Department of Valle del Cauca. Gathered information were used to develop qualitative models (i.e. causal loop diagrams) and quantitative models (stock and flow diagrams) in order to built a mechanistic model aimed to improve understanding of the multiple interactions and synergies that constitute the local agro-ecosystems. It includes the livestock and landscape components and their interaction influencing the ecosystem. The developed model evaluated three alternative scenarios of management with eventual economic incentives to farmers: i) business as usual; ii) incentive for areas destined to preservation; iii) areas released for restoration and future conservation. The main results showed that the proposed PES are a viable strategy for obtaining additional income for the land owners and they would also contribute to the maintenance of the typical natural coverage of the territory. However only considering economic balances, the opportunity cost of reducing livestock farming to preserve land is lower than cost of expected preservation. It might impair the choice of modifying the preferences of land use within the farms. The novelty of the study was the use of a system dynamic model to evaluate future sustainable patterns of PES to prevent side effects on the Colombian mountain area from a social and environmental point of view.