Variability in Fruit Production of Carapa guianensis Associated with Edaphoclimatic Factors in the Amazon

Abstract

Carapa guianensis Aubl., widely distributed throughout the Amazon, is recognized for its ecological, economic, and social importance, and constitutes a key source of income for numerous extractive communities. However, fruit production exhibits marked spatial variation that may be influenced by soil properties and climatic factors. In this study, we assessed this variability using data from 21 studies conducted in the Brazilian Amazon, incorporating georeferenced information from each site on climate and soil characteris- tics. Environmental variables were evaluated using Random Forest models. Although the number of independent production estimates available in the literature is limited, average fruit productivity showed a broad range (0.34 to 34.6 kg·tree−1·year−1), with higher values in várzea forests (16.5 kg·tree−1·year−1) and lower values in igapó forests (2.5 kg·tree−1 ·year−1). The Random Forest model explained 42% of the variability in fruit production according to cross-validation, whereas the model fit using the full dataset showed a higher R2 value (0.83). Soil organic carbon, mean annual temperature, and clay content were the most influential predictors. These findings demonstrate that fruit production is shaped by the interaction between edaphic and climatic conditions, which determine the species’ productivity patterns and highlight the need to foster adaptive management strategies that ensure the sustainable use of andiroba across Amazonian ecosystems. Nevertheless, it is acknowledged that the number of available production estimates is limited and that methodological heterogeneity exists among the analyzed studies. Despite this, the results reveal consistent patterns of association between Carapa guianensis fruit production and edaphoclimatic gradients, highlighting the influence of climatic and soil-related variables at a regional scale.