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Increased hydraulic constraints in Eucalyptus plantations fertilized with potassium
Author(s) -
Guillemot Joannès,
Asensio Verónica,
Bordron Bruno,
Nouvellon Yann,
le Maire Guerric,
Bouillet JeanPierre,
Domec JeanChristophe,
Delgado Rojas Juan Sinforiano,
AbreuJunior Cassio Hamilton,
BattieLaclau Patricia,
Cornut Ivan,
Germon Amandine,
De Moraes Gonçalves José Leonardo,
Robin Agnès,
Laclau JeanPaul
Publication year - 2021
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.14102
Subject(s) - transpiration , eucalyptus , throughfall , human fertilization , environmental science , agronomy , potassium , water use , biomass (ecology) , botany , biology , photosynthesis , chemistry , soil water , soil science , organic chemistry
Fertilization is commonly used to increase growth in forest plantations, but it may also affect tree water relations and responses to drought. Here, we measured changes in biomass, transpiration, sapwood‐to‐leaf area ratio ( A s : A l ) and sap flow driving force (Δ Ψ ) during the 6‐year rotation of tropical plantations of Eucalyptus grandis under controlled conditions for throughfall and potassium (K) fertilization. K fertilization increased final tree height by 8 m. Throughfall exclusion scarcely affected tree functioning because of deep soil water uptake. Tree growth increased in K‐supplied plots and remained stable in K‐depleted plots as tree height increased, while growth per unit leaf area increased in all plots. Stand transpiration and hydraulic conductance standardized per leaf area increased with height in K‐depleted plots, but remained stable or decreased in K‐supplied plots. Greater A l in K‐supplied plots increased the hydraulic constraints on water use. This involved a direct mechanism through halved A s : A l in K‐supplied plots relative to K‐depleted plots, and an indirect mechanism through deteriorated water status in K‐supplied plots, which prevented the increase in Δ Ψ with tree height. K fertilization in tropical plantations reduces the hydraulic compensation to growth, which could increase the risk of drought‐induced dieback under climate change.