Biotic and abiotic factors influencing the initial growth of Eucalyptus within agrosilvopastoral systems in the Brazilian Cerrado

Agrosilvopastoral (ASP) systems are sustainable production models for expansion in Brazil, and selecting the appropriate tree species is a fundamental requirement of ASP systems and a function of edaphoclimatic conditions. Therefore, this study aimed to analyze the biotic and abiotic factors that influence the initial growth and adaptation of two Eucalyptus genotypes ( Eucalyptus cloeziana and Eucalyptus urograndis ) intercropped with Sorghum bicolor and Urochloa brizantha in ASP systems in the Brazilian Cerrado. The damages, weaknesses, survival rates, diameters at soil height and breast height, and the total height of trees were evaluated over four years, considering rainy and dry periods. The data were analyzed using a correlation matrix and analysis of variance. Trigona spinipes and termites were the main biotic factors that caused damage and weakness in the E. cloeziana and E. urograndis genotypes, respectively. Eucalyptus urograndis showed a higher total height and diameter at breast height than E. cloeziana at 450, 630, 1020, and 1320 days after transplanting. Eucalyptus cloeziana had the highest survival rate (80.6%), whereas E . urograndis was more tolerant to water stress. Thus, even with severe termite attacks after sorghum harvest, E. urograndis was better adapted to the edaphoclimatic conditions in the present study and it is recommended in ASP systems in sites with high temperature and irregular rainfall distribution.