Fire and the functional organization of the tree community: Implications for forest resilience in the Tapajós-Arapiuns RESEX

Community Ecology, Functional Traits, Ecological Resilience

Tropical forests are responsible for global sustainability. In this context, fire emerges as a threat because it affects not only fire-vulnerable species, but also the taxonomic and functional compositions of communities, alters landscape structure, limits the maintenance of biodiversity, and provision of essential ecosystem services. This study aimed to understand how tree vegetation responds to fire, through functional attributes, and what are the implications for the resilience of the Amazon forest. The study was conducted in the Tapajós-Arapiuns Extractive Reserve, located in the western region of Pará State, Brazil. In 13 forest plots, ten burned in 2015/2017 and three unburned (control areas), for these plots, the most abundant species (i.e., species that, when summing their relative abundances, make up 50% of total abundance) that make up the first and second strata of the tree component, had 12 functional attributes evaluated (e.g., bark thickness, resprouting ability, wood density). Our study indicates that fire has a significant impact on the structure and composition of humid tropical forests in the Amazon, affecting both the taxonomic composition and the functional attributes of the tree component. Furthermore, the effects of fire can vary according to the forest stratum. It is important to emphasize that these results highlight the importance of conserving humid tropical forests and preventing fires, since the impacts of these events can be long-lasting and deeply affect the biodiversity and functioning of these ecosystems.