Stretching perspectives on rubber sustainability: ecological, economic, and social dimensions of tropical agriculture expansion and voluntary sustainability initiatives

Agricultural expansion is a major source of tropical deforestation. In particular, export commodity crops are often associated with environmental and socioeconomic problems in producer countries. This thesis focused on natural rubber, applying a multi-disciplinary lens to study the potential for aligning ecological, economic, and social sustainability goals. Using quantitative spatial analyses methods, I identified strong trade-offs between biodiversity and economic interests for future rubber expansion in Africa, Asia, and New Guinea. There is little room for new plantations in the most suitable areas for growing rubber that do not also threaten vulnerable species. Next, I used a spatio-temporal economic model to study the interactions between market prices, agricultural rents, rubber expansion, and protected areas during the latest rubber price boom and bust cycle in mainland Southeast Asia. Agricultural rents, incorporating changes in market prices, explained much but not all of the rubber expansion patterns across all countries in the study, highlighting the influence of socio-political variables in land-use changes. Protected areas hindered rubber expansion, but even the strictest reserves could not fully prevent encroachment especially in the most suitable and accessible lands. Lastly, I examined the process and implications of more inclusive and participatory stakeholder engagement in a multi-stakeholder sustainability initiative for rubber. Using document analysis, I map out the evolution of inclusiveness in the Global Platform for Sustainable Natural Rubber (GPSNR). The qualitative case study highlighted changes in membership composition, geographical representation, governance of decision-making, and the quality of smallholder participation. I documented gradual improvements in each component of inclusiveness, but challenges remain around equity of pricing and full participation of smallholders. This thesis offers a diverse contribution of perspectives, demonstrating how deforestation, agricultural demand, and equitable livelihoods are inextricably linked and emphasising the importance of multi-disciplinary approaches in theory and practice.