Intensification of tropical fallow-based agriculture: Trading-off ecosystem services for economic gain in shifting cultivation landscapes?

摘要

Farmers are under ever growing pressure to increase productivity to meet both food and fibre needs, as well as rising household economic demands. In many shifting cultivation systems, farmers are taking advantage of restorative forest fallow periods to plant commercially-oriented orchards to increase output. While there is an economic benefit to this intensification pathway, we ask: what are the trade-offs in ecosystem services with planting low diversity orchards? We compare the capacity of native forest fallows vs. planted umart orchards (Poraquieba sericea) to provide critical regulating services (soil fertility regeneration, woody biomass accumulation), provisioning services (commercial fruit production, timber, charcoal, wild fruits and handicraft materials production), and tree biodiversity in lowland forests of Peru. In addition, we estimate their potential contribution to farmer livelihoods to better understand the economic incentives behind orchard planting. Orchards were found to provide similar or higher levels of both regulating and provisioning services than forest fallows, apart from harvestable timber. Although biodiversity was lower under orchards, tree diversity and composition recovered fully in subsequent fallow rotations. Potential revenues from orchard planting were greater than from fallows, however they were small compared to median incomes suggesting that the motivation to plant orchards is income diversification. Together these results highlight that orchard fallows may be an ecologically and economically viable pathway for intensification. (C) 2015 Elsevier B.V. All rights reserved.