Assessing the Role of Plant Seasonalities on the Regional Organisation of the Tapajó Society

Human food practices involve procurement and production activities, including cleaning, planting, weeding, fertilisation, irrigation, and management, all influenced by seasonality. Plant phenology is the main seasonality index in Amazonian food production. This exploratory study reviews Tapajó archaeobotanical data to estimate how seasonal planting and harvesting affected regional organisations. The data originate from four Tapajó habitation sites dated ∼1000 cal BP in riverine and upland locations. Phytolith and macrocharcoal (>125 um) review identify 6 annual species and 25 perennials. Using Amazonian ethnobotanical data and plant phenology, we estimate each species’ planting and harvest/fruiting seasons. Generally, planting occurred in the rainy season and harvesting in both seasons. Zea mays, Manihot sp., and Cucurbita sp. were grown year-round in upland areas during the rainy season and floodplains during the dry season, being harvested throughout the year, while Maranta arundinacea, Goeppertia sp., and Oryza sp. were only harvested in the rainy season. Perennials bear fruit mainly in the wet season, although several species, including cacao and passion fruit, have off-season harvests in the dry season. We propose that the Tapajó regional organisation involved constant community movements, dwelling on their landscapes through seasonal interactions with floodplain and upland forests, marked by plant food cycles.