Relação entre diâmetro do caule e espessura da casca das árvores amazônicas e sua implicação na resistência ao fogo

Abstract

The characteristics of plants are important for understanding their functions and relationships with the environment and the functioning of ecosystems. Tropical forests, such as the Amazon, are important for promoting ecosystem services that are important for maintaining biodiversity and human well-being. However, these forests are facing major threats due to human interference, especially climate change and forest fires. Therefore, given this scenario, research focused on forest resistance to disturbance regimes can help in the monitoring and conservation processes of this type of biome. Therefore, the aim of this study was to evaluate the relationship between stem diameter at breast height (DBH) and bark thickness in tropical Amazonian forests, in order to identify the significance of the relationship between these variables and the possible effects on the degree of forest resistance to fire. The study was carried out using forest inventory data from 21 plots in the Lower Tapajós, in the Eastern Amazon - PA. In order to assess the relationship between DBH and bark thickness, data from 11 botanical families was used in a GLMM (Generalized Linear Mixed Effect Models). The relationship between the variables was significant, with an overall explanatory power of 34% for DBH over thickness, and considering the variation between botanical families, this power increased to 50%. Our results show that of the 11 botanical families studied, only half have trees with bark thick enough to be considered resistant (17-23 mm). In addition, in order to consider trees with or without resistance potential, we analyzed bark thickness at a minimum DBH of 10 cm and the increase in bark thickness as DBH increased. Fabaceae, Lecythidaceae and Burseraceae stood out as being more prone to fire mortality. Therefore, considering the high distribution of individuals belonging to these families in the Amazon and the current scenario of forest degradation, ecological impacts and climate change, this work raises insights into the Amazon's forest vulnerability to burning regimes, and the importance of its conservation for climatic conditions on a local and global scale.