Long-term Effects of Forest Management on Hydrochemical Fluxes: Insights from the TERENO Wüstebach Experiment

Although the hydrological impacts of land use changes are well studied, few datasets comprehensively capture the influence of land management on hydrochemical processes and solute fluxes. The long-term Wüstebach catchment experiment within the TERENO network (TERrestrial Environmental Observatories) provides a unique infrastructure for monitoring key water balance components, numerous anions and cations, as well as spatiotemporal soil moisture—both before and after partial deforestation and subsequent forest management measures such as thinning and underplanting.We present long-term hydrochemical observations, including macro- and micronutrients, dissolved aluminum, and dissolved organic carbon, collected three years before and thirteen years after deforestation. Hourly concentrations and fluxes were estimated using the R package LOADFLEX. Predicted nitrate concentrations were compared with high-resolution reference data to select the optimal modeling approach. Comparable flux data were determined for a neighboring reference catchment with similar characteristics but without clear-cutting, enabling the isolation of deforestation and reforestation effects on nutrient cycling and transport.Using flux data from both catchments, we applied a Before–After–Control–Impact (BACI) framework to quantify hydrochemical responses and feedbacks to forest management. Three phases were distinguished: pre-deforestation, the first two years after deforestation, and a later post-deforestation phase (three years after). The BACI analysis revealed distinct short- and long-term responses in solute fluxes, with the strongest effects observed for NO₃⁻, dissolved organic carbon (DOC), and Fe. Notably, fluxes during the two-year period immediately following deforestation differed significantly from both the pre-deforestation phase and the later post-deforestation phase, indicating a pronounced but transient disturbance effect. This dataset offers valuable opportunities to investigate the long-term impacts of deforestation and reforestation on hydrochemical fluxes under varying climatic conditions. Bogena, H.R., F. Herrmann, A. Lücke, T. Pütz and H. Vereecken (2025): Long-term hourly stream-water flux data to study the effects of forest management on solute transport processes at the catchment scale. Earth Syst. Sci. Data. 17: 6965–6992. DOI: 10.5194/essd-17-6965-2025