Increased hydraulic constraints in Eucalyptus plantations fertilized with potassium

Author(s):Show less -

Guillemot, Joannes ^{[1, 2, 3]} ; Asensio, Veronica ^{[3, 4, 5]} ; Bordron, Bruno ^{[1, 2, 3]} ; Nouvellon, Yann ^{[1, 2, 3]} ; le Maire, Guerric ^{[6, 1, 2]} ; Bouillet, Jean-Pierre ^{[1, 2, 3]} ; Domec, Jean-Christophe ^{[7, 8]} ; Delgado Rojas, Juan Sinforiano ^[3] ; Abreu-Junior, Cassio Hamilton ^[4] ; Battie-Laclau, Patricia ^{[3, 4]} ; Cornut, Ivan ^{[1, 2, 9]} ; Germon, Amandine ^{[10, 1, 2]} ; de Moraes Goncalves, Jose Leonardo ^[3] ; Robin, Agnes ^{[10, 1, 2, 3]} ; Laclau, Jean-Paul ^{[1, 2]}

Affiliation

^[1] CIRAD UMR Eco & Sols, Montpellier - France

^[2] Univ Montpellier, Montpellier SupAgro, INRAe, CIRAD, Eco & Sols, IRD, Montpellier - France

^[3] Univ Sao Paulo, Luiz de Queiroz Coll Agr USP ESALQ, Dept Forest Sci, Ave Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[4] Univ Sao Paulo USP CENA, Ctr Nucl Energy Agr, Piracicaba - Brazil

^[5] Edafotec SL, Vigo - Spain

^[6] Univ Estadual Campinas, NIPE, Campinas, SP - Brazil

^[7] Bordeaux Sci Agra, UMR INRAe ISPA 1391, Gradignan - France

^[8] Duke Univ, Nicholas Sch Environm, Durham, NC - USA

^[9] Univ Paris Sud, Univ Paris Saclay, AgroParisTech, CNRS, Ecol Systemat Evolut, Orsay - France

^[10] UNESP Sao Paulo State Univ, Sch Agr Sci, Botucatu, SP - Brazil

• Document type: Journal article
• Source: PLANT CELL AND ENVIRONMENT; JUN 2021.
• Web of Science Citations: 0

Abstract

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 (Delta psi) 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 Delta psi 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. (AU)

• FAPESP's process: 13/25998-4 - Influence of potassium fertilization and hydraulic redistribution by deep roots on the availability of water and nutrients from Eucalyptus
• Grantee: Verónica Asensio Fandiño
• Support type: Scholarships in Brazil - Post-Doctorate