The effects of land use and climate change on diameter of Dipteryx alata (Leguminosae) in the Brazilian Cerrado

Diameter at breast height (DBH) is related to various other plant attributes (e.g., height, fruit number, age), and as such, it can indicate important characteristics for species management and conservation. In this study, we aimed to investigate how the DBH of Dipteryx alata Vogel (Leguminosae) varies spatially across the Cerrado biome. Additionally, we examined how environmental factors and land use can influence the variation in DBH of the D. alata. Furthermore, we estimated the current and future potential distribution of D. alata to assess the impact of global climate change on the species' distribution. We utilized a database with 253 records of DBH for D. alata distributed across the Cerrado. For each sample unit, we determined the environmental suitability of D. alata using niche modeling, and land use was characterized and classified into different types (from pasture to remnant vegetation). Our results revealed that the DBH of D. alata ranged from 5 to 75 centimeters, and there was no discernible spatial pattern. Environmental suitability could not predict the spatial variation in DBH. Nonetheless, plants with larger DBH were found in regions classified as pasture in terms of land use. Factors such as reduced competition soil management and age of plants (old plants) may help explain why DBH was greater in pasture areas. It is worth noting that although pasture areas can serve as a refuge for some trees, proper management is essential to promote individuals' recruitment, ensuring population regeneration and the maintenance of diversity in long time. Climate projections anticipate significant loss of climatically suitable areas for D. alata in future scenarios.