Changing Perceptions of Risk: The Development of Agro‐Ecosystems in Southeast Asia

New long‐term environmental sequences for Southeast Asia provide a basis for reevaluating the development of agroecosystems. Previous models depict agricultural development as a singular, relatively rapid response to various stimuli such as climate change and population growth. In contrast, the Southeast Asian data indicate that the development of tropical agro‐ecosystems are the result of stresses separated in time and not part of a unitary developmental process. Two phases are evident: At the end of the Pleistocene, environmental data indicate a significant climatic change that would have affected the distribution of food resources. In some areas, this encouraged food production as previous food resources decreased or disappeared. In the second phase, during the mid‐ Holocene, increased cultural and social risks led to shifts in strategies that created agro‐ecosystems—a more fundamental transformation of landscape ecology. This distinct two‐phase pattern suggests groups were responding to very different challenges in each period These findings underscore the need to reexamine agricultural models that conflate separate and distinct processes of cultural change. [Keywords: Southeast Asia, tropical land use, phytoliths, agriculture, Thailand]