Campo Alegre is one of the largest swidden communities in the ethnographic record of Amazonia and over the past generation residents have come to make their gardens in some of the youngest recorded fallows. Fieldwork examined the nature of intensification in Campo Alegre÷ specifically the relations among fallow maturity, agroecology and work-effort÷ from both etic and emic perspectives. Etic evidence presented supports much dominant intensification theory, but suggests a modification regarding changes in clearing work-effort. Emic evidence presented shows strong parallels to etic findings. However, informants gave far greater emphasis to changes in work-experience than to changes in work-rates or returns-to-labor. Informant understandings of intensification÷expressed in classifications of plants and soils, and in associations of these taxa with relative fallow maturity÷are based on intimate interactions with these taxa in the context of agricultural work.

Keywords: swidden agriculture, intensification, work experience, folk classification, Amazonia