Journal Article

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

Jean-Christophe Domec, Yann Nouvellon, Jean-Pierre Bouillet, Rildo Moreira e Moreira, Jean-Marc Bouvet, Patricia Battie-Laclau, Marisa de Cassia Piccolo, Alex Vladimir Krusche, José Leonardo de Moraes Gonçalves, Jean-Paul Laclau, Mathias Christina

2014

Overview

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 3 yr 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.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc,Wiley
• Subject: Adaptation, Physiological - drug effects / Agriculture / Biological fertilization / Biomass / biomass production / Brazil / Climate / Conductance / Drought / Droughts / eucalypt / Eucalyptus / Eucalyptus - drug effects / Eucalyptus - growth & development / Eucalyptus - physiology / Eucalyptus grandis / Fertilization / Leaf area / Leaf area index / Leaves / Life Sciences / Nutrition / osmotic adjustment / Phloem / Phloem - chemistry / Phloem - metabolism / Plant Leaves - physiology / Plant Stomata - physiology / Plantations / Planting / Potassium / Potassium - pharmacology / rainfall exclusion / Resistance / Saccharides / sap / Seasons / Sodium / Sodium - pharmacology / Soil / Soil layers / Soil water / Soil water deficit / Soil water storage / Stomata / Stomatal conductance / stomatal movement / sugars / Throughfall / tree growth / tree nutrition / Trees / Turgor pressure / Vegetal Biology / Water deficit / water requirement / Water requirements / Water shortages / Water stress / Water supply / water utilization