Fragmented landscapes are becoming the norm in tropical regions. Understand how fragmentation can affect the ‘biodiversity-productivity’ relationship is essential to access the biomass budget and understand forest dynamics in these landscapes. Here, we used data from 108 permanent plots (4,000 m² each) of the National Forest Inventory to test the effect of tree species richness, species composition, leaf area index (LAI) and edge effect on biomass stock and change (5-year interval) in Santa Catarina, Brazil. We found an average biomass stock of 133.59 (± 67.24) Mg ha-1, and biomass change of 9.36 (± 12.08) Mg ha 5yr-1. Distance to forest edge interacted with species richness and composition limiting biomass stock, while LAI positively affected the stock. Biomass change increased in plots with higher number of pioneer species and located distant from the forest edge. Our results show how pervasive human pressure can be in fragmented landscapes.