Routing stemflow water through the soil: a dual labelling approach with artificial tracers

• DOI: 10.5194/hess-2022-382
• Publication Date: 2022-11-21T09:26:02Z
• Authors: Juan Pinos; Markus Flury; Jérôme Latron; Pilar Llorens
• Keywords: Stemflow; Macropore; Infiltration (HVAC)

Abstract. Few studies have explored the stemflow double-funnelling phenomenon, although subsurface flow along roots and macropores plays a significant role in determining hydrological responses forested catchments. In this study, experiment on Pinus sylvestris L. (Scots pine) used artificial tracers to view quantify preferential of water after infiltration into soil. Forty-one litres labelled with enriched deuterium Brilliant Blue FCF were applied at rate 7 L h-1 stem pine tree, which corresponds caused by about 50 mm rainfall. TDR probes distributed around tree trunk depth profiles measure high-resolution volumetric content. One day discharge, soil pits dug different cardinal directions varying distances from tree. Photographs taken for imaging analysis metrics. Soil samples analyse dye concentrations isotopic compositions. We found that infiltrated through an annulus-shaped area base. observed heterogenous spatiotemporal moisture response occurrence shallow perched tables trunk. Dye staining demonstrated primarily surface coarse also macropores. The coverage was less extensive close increased proximity Lateral observed, mainly layers. A set metrics prevalence flow. Deuterium correlated each other significantly. decreased increasing distance trunk, indicating dilution mixing residual water. Macropores, (living or decayed) produced complex network regulating Our results suggest heavily affects distribution, thus groundwater recharge runoff. study provides insights physical processes controlling belowground funnelling improves our understanding forest-water interactions.