Due to concerns about climate change, energy security, and resource scarcity, non- renewable resources are increasingly being displaced by biomass. As with most human activities, the production of biobased products can be associated with negative impacts. Primarily, this relates to the biomass supply systems, i.e., agriculture and forestry, which currently are major causes of biodiversity loss and degradation of ecosystem services. Developing sustainable production systems when transitioning from non-renewable resources to biomass is imperative. This thesis aims to clarify the meaning of sustainability in the context of biomass for bioenergy, and contribute to our understanding of how different forms of governance can promote sustainably sourced biomass for bioenergy. The thesis is based on five appended papers: Paper I analyses to what extent, where, and under what conditions oil palm for biodiesel in Brazil can be produced profitably, and what risks and opportunities that can be associated with introducing large-scale oil palm production in Brazil. Paper II lays the foundation for understanding how new biomass production can be introduced into landscapes while supporting rather than compromising the ability of the landscape to supply other ecosystem services. Paper III describes different forms of governance and shows how these can play different roles in promoting sustainable bioenergy in different countries. Paper IV focuses on how short rotation coppice production systems are affected by EU policy and how different governance forms can assist in adapting production systems to conform to the corresponding sustainability requirements. Finally, Paper V assesses how sustainability certification (private governance) addresses biodiversity conservation and contributes to our understanding of possible improvements.