Greetings. The manuscript entitled “Hillslope subsurface flow is driven by vegetation more than soil Properties in colonized valley moraines along a humid mountain elevation” deals with the role of the vegetation, and its potential prevalent impact, on subsurface flow pathways. The structure and goals are clear, and the results offering is well-suited. This paper can for sure be published after some adjustments, listed below. I think that these itemized improvements would make the work more scientifically sound and robust. These considerations come from my expertise as a hydrogeologist, so they will pertain to this sphere of competency. Best regards.

• It is interesting to notice that the root structures are highly spatially heterogeneous, while the soil layers that have been taken are (if I understood correctly) homogeneous. This setup is highly debatable and should be sustained somehow. We know that the first dozen of centimeters below ground are highly randomly formed and have a lot (a lot!) of strongly non-homogeneous features (see e.g. Li et al., 2022), like mole-holes, worm-holes, cracks and fissures, small drainage pipes occurring for example, when some roots dry and die. Please comment extensively and adequately within the Introduction and highlight where these points may (or may not) impact the methodology.
• On the other side, I do agree that the roots are (some of the) preferentially heterogeneous features at THIS spatial scale. I would introduce that there may be various scales of inspection, each of them dealing with various features that rule preferential pathways spatial distribution (at the micro-scale, pores irregularity and chemical weathering, as in Shavelzon et al., 2025; at the root scale, roots, mole-holes, etc, as in Li et al., 2022; permeable sediments organized as preferential pathways, as in Schiavo, 2023).
• Were parameters in tables 1 and 2 calibrated?
• Please add R2 coefficients to the fitted data in Figure 4.
• I think that more should be said about preferential pathways at the planar (not vertical) scale. Even if the root apparatus is mainly vertical, its horizontal component, due to the angle of the setup, makes the horizontal highly permeable zone not negligible. This would play as a planar preferential pathway, such as those recognized at the microscale (Shavelzon et al., 2025) and at the catchment scale (Schiavo, 2023). I think that commenting more and relating these works would serve to somehow ‘close the circle’ among different perspectives and spatial scales in hydrology.
• In Figure 5, every time you have a more intense rainfall event, the model somehow slightly fails in predicting the flow. Can you comment on this? Which fixings and adjustments could be implemented?
• My ending feeling is, to be honest, that the absence of flow heterogeneity plays a crucial role in letting the root apparatus play a major role in the subsurface flow. I think more work should be implemented to convince the reader of this point. How to implement heterogeneity? What about the vast literature implementing Monte Carlo-based models to deal with the inherent groundwater heterogeneity, which is due to geological heterogeneity?

References:

Li, W., Germaine, J. T., & Einstein, H. H. (2022). A three-dimensional study of wormhole formation in a porous medium: Wormhole length scaling and a Rankine ovoid model. Water Resources Research, 58, e2021WR030627. https://doi.org/10.1029/2021WR030627

Schiavo, M., 2023. Entropy, fractality, and thermodynamics of groundwater pathways. J. Hydrol. 617 (4), 128930. DOI: 10.1016/j.jhydrol.2022.128930

Further reading:

Shavelzon, E., Edery, Y., and Zehe, E., 2025. Linking evolution of preferential flow paths, transport self-organization and chemical weathering in porous media using non-equilibrium thermodynamics. Goldschmidt 2025 Conference, Prague.

Dear authors,

this work is interesting and could bring a valuable contribution to the scientific discussion about hillslope hydrology. In my opinion it could be published after some adjustments.

Please find my edits in the attached file, plus I quote every single note by Ref#1 and I suggest you double check the writing of the entire manuscript one more time, as some sentences make little sense and I am not sure some words are used properly.

Regards