Timber-based agrisilviculture improves financial viability of hardwood plantations: a case study from Panama

Abstract

Tree plantations are widely considered a sustainable and economically feasible way to foster reforestation of degraded tropical lands. However, the greatest obstacle to their implementation is the 5–10 years period before initial returns through tree harvesting are realized. This study evaluated the feasibility of generating returns in this period by intercropping hardwood plantations with annual crops. In an agroforestry trial established in eastern Panama, the costs and revenues of intercropping five native and one exotic (Tectona grandis) tree species with three different agricultural treatments––maize-beans, pigeon pea and cassava––were assessed. All tree-crop combinations, except those with cassava, generated positive net cash flows during the first years. Over the modeled rotation period of 25 years, the agrisilvicultural systems showed up to 50 % higher net present values (NPV) than pure forestry (given a 6 % interest rate), while most tree-crop combinations exceeded the NPV of pure agriculture. T. grandis intercropped with pigeon pea showed the best economic performance. The NPVs of the agrisilvicultural systems were less sensitive to changes in costs or revenues than either pure forestry or pure agriculture. Accordingly, the final felling value required for intercropping treatments to meet the desired interest rate of 6 % was up to 90 % lower than that for pure forest plantations. This effect was strongest for native tree species, as their slower growth allowed for longer periods of intercropping. Results suggest that intercropping hardwood plantations can be an effective tool for improving financial feasibility of reforestation while providing increased food security in rural areas.