Increased hydraulic constraints in Eucalyptus plantations fertilized with potassium.

Journal Article (Journal Article)

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 (As :Al ) and sap flow driving force (ΔΨ) 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 Al in K-supplied plots increased the hydraulic constraints on water use. This involved a direct mechanism through halved As :Al 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 ΔΨ 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.

Full Text

Duke Authors

Cited Authors

  • Guillemot, J; Asensio, V; Bordron, B; Nouvellon, Y; le Maire, G; Bouillet, J-P; Domec, J-C; Delgado Rojas, JS; Abreu-Junior, CH; Battie-Laclau, P; Cornut, I; Germon, A; De Moraes Gonçalves, JL; Robin, A; Laclau, J-P

Published Date

  • September 2021

Published In

Volume / Issue

  • 44 / 9

Start / End Page

  • 2938 - 2950

PubMed ID

  • 34033133

Electronic International Standard Serial Number (EISSN)

  • 1365-3040

International Standard Serial Number (ISSN)

  • 0140-7791

Digital Object Identifier (DOI)

  • 10.1111/pce.14102


  • eng