Exploring tropical forest aboveground carbon dynamics via modelled landscapes of varied food production, past and present

Societal Impact Statement Contemporary land use studies often place food production in direct conflict with tropical forests, with forest land use for human needs exiting in conflict with carbon‐related forest conservation and biodiversity protection efforts. We highlight the more nuanced, mixed activities possible in the space between primary forest and fixed, monocultures that were, and are, practiced by Indigenous communities from the deep past into the present. Given the increasingly clear importance of the tropics to human history and contemporary human sustainability, this work has key implications for understanding past human‐environment processes, empowering Indigenous stewardship and informing forest conservation policy. Summary Tropical forests are key components of the global carbon cycle given their considerable carbon stocks. Agriculture is often seen as in major conflict with tropical forests, with carbon budget models highlighting dramatic carbon stock losses with the conversion of land for food. However, these models often focus on monocultural cropping systems, while the archaeological and historical records highlight more varied forms of food production in tropical forests from at least 8,000 years ago. Here we develop a simple model to simulate relative aboveground carbon (AGC) values for a tropical forest anthrome with varied food production practices. We examine past examples of tropical land use activities including understory thinning, selective agroforestry and various swidden patterns. We compare these to old‐growth forests, open cropping and plantation systems. Results highlight the importance of retaining large trees to AGC. Understory thinning practices have a limited effect on AGC by mainly impacting small trees. Regular, short fallow swidden drastically reduces AGC, while irregular, long fallow swidden can maintain AGC half that of old growth forest. A mosaic landscape of forest food production can maintain much higher long‐term mean AGC values than is typically assumed for carbon budgets of past land use.