My PhD research will address the major factors that influence scheduling of conservation action over time. This task is common practice in conservation because fully implementing multiple conservation actions requires human and monetary resources that are rarely available at one time. Therefore, conservation planners are required to set priorities for conservation, selecting what to protect first and what to leave for the future. However, several simplifications are commonly made when setting priorities. These simplifications regard both the socio-economic and the ecological aspects of biodiversity conservation. In my PhD project, I will first identify the most common assumptions made in dynamic conservation planning. Secondly, I will examine how to address these assumptions by explicitly considering the complexities ignored in conservation decision-making. My focus will be on assumptions related to the value of considering future patterns of human-driven habitat loss and fragmentation, the biodiversity responses to habitat loss and fragmentation, and the emerging properties of reserve networks that arise when addressing both habitat loss and connectivity. My research will have important implications in both theory and practice. By testing different hypotheses and assumptions regarding the behaviour of existing conservation planning strategies and suggesting new approaches for environmental decision-making, I will contribute to the theoretical advancement of the discipline. At the same time, I will derive rules of thumb and recommendations on optimal priority setting for conservation practitioners, which are likely to have important practical consequences for conservation decisions at local to global scales.