Insofar as warfare ecology aims to examine all war-related conditions, belligerent occupations are a necessary stage in its broad taxonomy. Under international law, belligerent occupations are covered by a distinctive subset of jus in bello (humanitarian law), which is imprecise regarding ecological changes. This chapter examines the potential role of warfare ecology in studying belligerent occupations, highlighting the multiple, often indirect, means by which such occupations shape ecological processes. Particular attention is paid to the Israeli occupation of Palestinian territory, due to its protracted duration, although also discussed are environmental effects associated with the US and UK occupation of Iraq. The onus on the occupying power, under international humanitarian law, to protect the conditions of life for civilians can plausibly be applied to the environmental resources of the resident population. It is argued that warfare ecology can make a significant contribution both to assessing the effects of occupations and, through the generation of policy advice, to promote conflict outcomes more sensitive towards ecological processes.