Richness and composition of terrestrial mammals vary in eucalyptus plantations due to stand age

Plantation forests substitute natural habitats and have rotation cycles of 7 years due to their high growth rates. This variation reflects on local and landscape changes, influencing habitat availability and affecting mammal communities. In this study, our general hypothesis was that the richness and composition of mammals varied in eucalyptus plantations in relation to native forest patches and in relation to the age of eucalyptus plantations. We predicted that (1) there would be lower mammalian richness and compositional differences in eucalyptus plantations compared to native vegetation due to monocultures having simplified environmental characteristics and (2) predicted that the richness and composition would vary according to eucalyptus age and that the highest values of richness would be found in plantations of up to middle age, considering that in these phases there are environmental characteristics that positively qualify these structures for a greater presence of fauna, such as the shrubby aspect of the plantations and the presence of undergrowth. We performed model selection to observe the effect of environmental variables on mammalian richness. We also performed a multivariate permutational analysis of variance, a non-metric multidimensional scaling and partitioned the beta diversity to observe how the composition was influenced by environmental variables. We found greater richness in the native vegetation compared to eucalyptus plantations. The richness of the plantations varied according to the age, with higher values up to middle age. The composition varied according to the land user/cover, with the eucalyptus age and with the management unit due to the nestedness of species. We suggest that eucalyptus plantations at early ages are more used by mammals due to the shrubby aspect of the stand, generating a positive visual effect for the search of resources and shelter, in addition to the possibility of the occurrence of grasses, some understory and lower anthropogenic disturbance.