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Investigating the root plasticity response of Centaurea jacea to soil water availability changes from isotopic analysis
Author(s) -
Kühnhammer Kathrin,
Kübert Angelika,
Brüggemann Nicolas,
Deseano Diaz Paulina,
Dusschoten Dagmar,
Javaux Mathieu,
Merz Steffen,
Vereecken Harry,
Dubbert Maren,
Rothfuss Youri
Publication year - 2020
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.16352
Subject(s) - transpiration , environmental science , soil water , water content , plant root , soil science , transpiration stream , root system , water flow , agronomy , botany , biology , photosynthesis , geology , geotechnical engineering
Summary Root water uptake is a key ecohydrological process for which a physically based understanding has been developed in the past decades. However, due to methodological constraints, knowledge gaps remain about the plastic response of whole plant root systems to a rapidly changing environment. We designed a laboratory system for nondestructive monitoring of stable isotopic composition in plant transpiration of a herbaceous species ( Centaurea jacea ) and of soil water across depths, taking advantage of newly developed in situ methods. Daily root water uptake profiles were obtained using a statistical Bayesian multisource mixing model. Fast shifts in the isotopic composition of both soil and transpiration water could be observed with the setup and translated into dynamic and pronounced shifts of the root water uptake profile, even in well watered conditions. The incorporation of plant physiological and soil physical information into statistical modelling improved the model output. A simple exercise of water balance closure underlined the nonunique relationship between root water uptake profile on the one hand, and water content and root distribution profiles on the other, illustrating the continuous adaption of the plant water uptake as a function of its root hydraulic architecture and soil water availability during the experiment.