Impacto das mudanças no uso do solo em plantações de eucalipto na diversidade e nos serviços ecossistêmicos de besouros rola-bosta

Abstract

The conversion of natural ecosystems into eucalyptus plantations alters environmental conditions and can impact communities of key functional groups, such as dung beetles (Scarabaeinae). This study investigated how managed and abandoned eucalyptus plantations influence the diversity and ecosystem services of these insects in mountainous environments of the northern portion of the Espinhaço Mountain Range, Minas Gerais. Areas of native vegetation (reference), active eucalyptus plantations, and abandoned cultivation areas were compared. The following predictions were tested: i) beetle diversity would be highest in reference areas, followed by abandoned eucalyptus areas, and then current eucalyptus plantations; ii) sandier soils would have lower beetle diversity; and iii) ecosystem services would be greatest in reference areas, followed by abandoned areas, and then eucalyptus plantations. Beetle diversity was assessed using pitfall traps baited with pig feces, while ecosystem services such as organic matter removal, secondary seed dispersal, and soil aeration were quantified in experimental arenas. Soil samples were analyzed to characterize the physical-chemical properties of the treatments. Average abundance and richness were higher in reference areas and abandoned plantations, highlighting the potential for fauna recovery in these locations. Permutational Analysis of Variance (PERMANOVA) indicated significant differences in species composition between treatments, and Indicator Value (IndVal) analysis identified one indicator species in reference areas and six in abandoned areas, but none in managed plantations. Principal Component Analysis (PCA) revealed that soils in eucalyptus areas had higher fertility, while linear regression showed that the percentage of sand negatively affected beetle diversity. Ecosystem services of organic matter removal and secondary seed dispersal did not differ between treatments, while soil aeration was greatest in eucalyptus areas, suggesting that services do not rely solely on taxonomic diversity. The results indicate that abandoned eucalyptus areas sustain high beetle diversity, similar to reference areas, while managed plantations have lower diversity. These findings highlight the importance of abandoned areas for the recovery of dung beetle fauna and suggest that more heterogeneous management practices could mitigate the negative impacts of eucalyptus monoculture on biodiversity.