Effects of potassium and sodium supply on drought-adaptive mechanisms in Eucalyptus grandis plantations

Author(s):Show less -

Battie-Laclau, Patricia ^[1] ; Laclau, Jean-Paul ^{[2, 3, 4]} ; Domec, Jean-Christophe ^{[5, 6]} ; Christina, Mathias ^{[3, 7]} ; Bouillet, Jean-Pierre ^{[2, 3]} ; Piccolo, Marisa de Cassia ^[1] ; de Moraes Goncalves, Jose Leonardo ^[2] ; Moreira e Moreira, Rildo ^[2] ; Krusche, Alex Vladimir ^[1] ; Bouvet, Jean-Marc ^[8] ; Nouvellon, Yann ^{[3, 9]}

Affiliation

^[1] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, BR-13418900 Piracicaba, SP - Brazil

^[3] CIRAD, UMR Eco&Sols, F-34060 Montpellier - France

^[4] Univ Estadual Sao Paulo Julio de Mesquita Filho, Dept Ciencia Florestal, BR-18610300 Botucatu, SP - Brazil

^[5] Bordeaux Sci Agro, INRA, ISPA, UMR 1391, F-33170 Gradignan - France

^[6] Duke Univ, Nicholas Sch Environm, Durham, NC 27708 - USA

^[7] Montpellier SupAgro, F-34060 Montpellier - France

^[8] CIRAD, AGAP, UMR, F-34398 Montpellier - France

^[9] Univ Sao Paulo, Dept Ciencias Atmosfer, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: NEW PHYTOLOGIST; v. 203, n. 2, p. 401-413, JUL 2014.
• Web of Science Citations: 37

Abstract

A basic understanding of nutrition effects on the mechanisms involved in tree response to drought is essential under a future drier climate. A large-scale throughfall exclusion experiment was set up in Brazil to gain an insight into the effects of potassium (K) and sodium (Na) nutrition on tree structural and physiological adjustments to water deficit. Regardless of the water supply, K and Na supply greatly increased growth and leaf area index (LAI) of Eucalyptus grandis trees over the first 3yr after planting. Excluding 37% of throughfall reduced above-ground biomass accumulation in the third year after planting for K- supplied trees only. E.grandis trees were scarcely sensitive to drought as a result of the utilization of water stored in deep soil layers after clear-cutting the previous plantation. Trees coped with water restriction through stomatal closure (isohydrodynamic behavior), osmotic adjustment and decrease in LAI. Additionally, droughted trees showed higher phloem sap sugar concentrations. K and Na supply increased maximum stomatal conductance, and the high water requirements of fertilized trees increased water stress during dry periods. Fertilization regimes should be revisited in a future drier climate in order to find the right balance between improving tree growth and limiting water shortage. (AU)