Using natural abundances of stable water isotopes to constrain vertically distributed root water uptake of forest trees

• DOI: 10.5194/ismc2021-101
• Publication Date: 2021-04-28T17:57:04Z
• Authors: Fabian Bernhard; Katrin Meusburger
• Keywords: Soil horizon; Lysimeter; Bulk soil

<p>The water balance in forest soils is strongly affected by vertical distribution of root uptake. Our objective to constrain the parametrization uptake field using naturally occurring, seasonal variability stable isotope signatures precipitation trace fluxes through soil and into trees.</p> 1D hydrologic model LWFBrook90.jl contains necessary processes accurately reproduce hydrometric observations volumetric moisture content matric potential at sites Switzerland. Root described with a gradient-driven vertically varying density moisture-dependent rhizosphere resistivities. The will be extended transport fractionation enable modeling isotopic tree water.</p> <p>We present planned sampling campaign over two subsequent vegetation seasons 10 long-term monitoring sites. Soil sampled lysimeters four depths, from xylem increment corers. Both types samples are taken bi-weekly. First results an ongoing multi-year show that signal can traced along profile presented illustrate approach.</p>