Using native timber trees for recovering degraded landscapes in the Philippines: social, biophysical and economic assessment of agroforestry systems practiced by smallholder farmers

This study was designed to gain a better understanding of the current land used decisions that lead to rapid conversion of tropical forest margins and the slow process of rehabilitation and development of sustainable land use practices on deforested areas in the past. The overall hypothesis is that “Using native timber for recovering degraded landscapes can result in land use that is both sustainable and productive” . Three main requisites need to be test to answer this general hypothesis. Are timber based agroforestry systems with native timber tree species (i) Socially acceptable; (ii) Biophysically feasible and; (iii) Economically profitable Thesis introduction present the big picture, describing what are the driving forces of deforestation and tree planting in the Philippines and other tropical countries especially in Southeast Asia. General and specific hypothesis and objectives are presented in Chapter 2 together with the overall framework and flow-chart of the thesis that guided the work. Chapter 3 presents the results from the socio-economic survey conducted among smallholder in four different upland communities revealing which are the major factors influencing farmers’ capacity and intention to plant timber trees. Chapter 4 presents data on where farmers are actually planting native timber tree species across the agricultural landscape a nd evaluates these results in relation to tree growth performance. Chapter 5 develop a tree database for the most promising native tr ee species and estimates above- ground tree biomass utilizing destructive and non- destructive methods which will allow further analysis using model simulations tools. Chapters 6 and 7 evaluate timber based agroforestry systems with native tree species from the biophysical and economic point of view. Chapter 6 presents biophysical results from model simulations and evaluates the feasibility and sustainability of a wide array of possible management options where trade-offs between tree growth and crop yield is presented in a simple and innovative format. Chapter 7 converts biophysical model simulations results into economic values (using ex ternal price data) and evaluates the profitability and risk resilience of each system under diffe rent macroeconomic conditions. Overall thesis conclusions are discuss in Chapter 8, where the consolidation of each individual chapter results lead to synthesized what are the policy and economic determinants needed to facilitate the forest transition that is likely to take place in the Philippines.

---

• Voir source