Drought and fire effects on the dynamics of gallery forests in the Cerrado-Amazonia transition
Gallery forests, plant dynamics, climate change, tree mortality
Rainfall is crucial to plant success, particularly for gallery forests that depend on moisture from waterways. However, extreme drought events and interaction with fire cause high mortality of tropical tree species, negatively impacting carbon accumulation and biodiversity. Our study, conducted over 22 years in the gallery forests of Parque Municipal do Bacaba, in Nova Xavantina, Mato Grosso, sought to quantify changes in plant structure and dynamics and evaluate the impacts of drought and fire events. We measured all trees with diameter at breast height (DBH) ≥ 5 cm, about diameter and height, in three plots of 0.5 ha each. We observed a reduction of 23 species (18.7%) and a 35.6% loss in the density of individuals from 1999 to 2021. Mortality rates increased, while recruitment rates did not compensate for the losses, indicating an imbalance in the ecosystem. The basal area showed a significant net change, but biomass remained almost unchanged. We conclude that the frequency of drought and fire events can have serious consequences for the structure and dynamics of gallery forests, leading to the replacement and even local extinction of species less tolerant to these disturbances.