Contrasting phenology of Eucalyptus grandis fine roots in upper and very deep soil layers in Brazil

Author(s):Show less -

Lambais, George Rodrigues ^[1] ; Jourdan, Christophe ^{[2, 3]} ; Piccolo, Marisa de Cassia ^[1] ; Germon, Amandine ^{[2, 4]} ; Pinheiro, Rafael Costa ^[4] ; Nouvellon, Yann ^{[2, 3]} ; Stape, Jose Luiz ^[5] ; Campoe, Otavio Camargo ^[6] ; Robin, Agnes ^{[7, 2]} ; Bouillet, Jean-Pierre ^{[2, 3]} ; le Maire, Guerric ^{[2, 3]} ; Laclau, Jean-Paul ^{[2, 3, 4]}

Affiliation

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Sao Paulo - Brazil

^[2] CIRAD, UMR Eco&Sols, F-34398 Montpellier - France

^[3] Univ Montpellier, Eco&Sols, CIRAD, INRA, IRD, Montpellier SupAgro, Montpellier - France

^[4] Sao Paulo State Univ UNESP, Sch Agr Sci, BR-18610300 Sao Paulo - Brazil

^[5] Itapetininga, Suzano Papel & Celulose Brasil, BR-18207780 Sao Paulo - Brazil

^[6] Univ Fed Santa Catarina, Dept Agr Biodivers & Forest, BR-89520000 Curitibanos, SC - Brazil

^[7] Univ Sao Paulo, ESALQ, BR-13418900 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: PLANT AND SOIL; v. 421, n. 1-2, p. 301-318, DEC 2017.
• Web of Science Citations: 5

Abstract

While the role of deep roots in major ecosystem services has been shown for tropical forests, there have been few direct measurements of fine root dynamics at depths of more than 2 m. The factors influencing root phenology remain poorly understood, creating a gap in the knowledge required for predicting the effects of climate change. We set out to gain an insight into the fine root phenology of fast-growing trees in deep tropical soils. Fine root growth and mortality of Eucalyptus grandis trees were observed fortnightly using minirhizotrons down to a soil depth of 6 m, from 2 to 4 years after planting. In the topsoil, the highest live root length production was during the rainy summer (20 cm m(-2) d(-1)) whereas, below 2 m deep, it was at the end of the dry winter (51 cm m(-2) d(-1)). The maximum root elongation rates increased with soil depth to 3.6 cm d(-1) in the 5-6 m soil layer. Our study shows that the effect of the soil depth on the seasonal variations in fine root growth should be taken into account when modelling the carbon, water and nutrient cycles in forests growing on deep tropical soils. (AU)

• FAPESP's process: 11/06412-3 - Fine root turnover in plantations in the Eucalyptus grandis in soils with different textures (Itatinga - SP)
• Grantee: George Rodrigues Lambais
• Support Opportunities: Scholarships in Brazil - Doctorate