Rodolfo Luiz Bezerra Nóbrega, Taciana Ziembowicz, Gilmar N. Torres, Alphonce C. Guzha, Ricardo S. S. Amorim, Domingos Cardoso, Mark Johnson , Túlio G. Santos, Eduardo G. Couto, Gerhard Gerold

The ecological services provided by protected riparian zones in human-altered landscapes are widely acknowledged, yet little is known about them. In this study, we assess ecosystem properties that a protected riparian zone maintains in contrast to environmental changes in its surroundings caused by agro-industrial activities in the northwestern fringe of the Brazilian Cerrado on the Amazon–Cerrado agricultural frontier. We assessed the plant biodiversity, soil hydro-physical properties, and water quality, to understand how the underlying ecological characteristics of a riparian zone withstand the effects of its neighboring cropland area on the stream water quality. We show that the riparian zone is fundamental in providing key ecosystem regulating services, including maintenance of plant biodiversity, soil properties, and water quality. Protection of plant biodiversity in the riparian zone sustains a synergy between soil, and functionally and phylogenetically diverse plant communities by promoting higher infiltration rates, higher soil porosity, and natural soil biogeochemistry conditions, which in turn have direct implications for stream water quality. Our study reaffirms that the conservation of riparian zones is crucial to buffer the negative impacts of agricultural practices on ecosystem services. Our results provide consistent evidence to support further studies and environmental policies for riparian environments, which are often the last fragment of natural vegetation remaining in the dominantly agricultural lands within the Cerrado and Amazon forests.