DOM optical properties reflected land use cover in open-canopy streams

Abstract

Our study aimed to analyze the effects of land use coverage (agricultural, cattle breeding, natural vegetation, and others) on the concentration and chemical characteristics of DOM in Pampean streams. We selected 41 streams situated in the Buenos Aires Province, Argentina in autumn, spring, and summer. In each stream, we determined DOC concentration and adopted a spectroscopic approach to characterize DOM optical qualitative properties. Agricultural land use coverage was predominant in all the sampled streams. Our results showed that DOC ranged from ~ 3 to 26 mg L−1, higher DOC concentrations were found in streams from Salado River and its tributaries. The variation in DOM properties was related to land use coverage and season. According to that, we found similar DOM optical properties during summer due to extremely high precipitation during the sampling period, suggesting higher hydrological connectivity between catchments and streams. The Pampean region is undergoing an agricultural intensification that affects the riparian zone of streams. This is the first study, which assesses the changes in DOM optical features concerning land use coverage in streams located in the Pampean region.