New Precipitation Is Scarce in Deep Soils: Findings From 47 Forest Plots Spanning Switzerland

Authors

Emily I. Burt, Chapman University
Scott T. Allen, University of Nevada, Reno
Sabine Braun, Institute for Applied Plant Biology, Switzerland
Simon Tresch, Institute for Applied Plant Biology, Switzerland
James W. Kirchner, Swiss Federal Institute for Forest, Snow and Landscape Research
Gregory R. Goldsmith, Chapman UniversityFollow

Document Type

Article

Publication Date

8-18-2025

Abstract

As precipitation infiltrates into soils, it can recharge them, displace previously stored waters, or bypass already-filled pores. Using 3,697 δ2H and δ18O measurements of water collected nearly monthly over >3 years in 47 forest plots across Switzerland, we present a systematic investigation of the controls on mobile soil water transport. We quantified the lags and damping of water as it percolates downward using young water fraction analysis (Fyw), and the fractions of soil water composed by precipitation that fell within the previous month (new water fractions, Fnew). The Fnew of water sampled in surface soils ranged widely, from 0% to 50%, but those fractions typically decreased with depth and converged on values of 0%–20% at depths below 80 cm. Soil characteristics explained much of the variation in Fyw and Fnew, as did climatological and root characteristics to a lesser, but still statistically significant, degree.

Comments

This article was originally published in Geophysical Research Letters, volume 52, issue 16, in 2025. https://doi.org/10.1029/2025GL115274

Recommended Citation

Burt, E. I., Allen, S. T., Braun, S., Tresch, S., Kirchner, J. W., & Goldsmith, G. R. (2025). New precipitation is scarce in deep soils: Findings from 47 forest plots spanning Switzerland. Geophysical Research Letters, 52, e2025GL115274. https://doi.org/10.1029/2025GL115274

Copyright

The authors

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