Nutrient supply modulates species interactions belowground: dynamics and traits of fine roots in mixed plantations of Eucalyptus and Acacia mangium

Author(s):Show less -

Bordron, B. ^{[1, 2]} ; Germon, A. ^{[3, 4]} ; Laclau, J-P ^{[5, 3, 4]} ; Oliveira, I. R. ^[1] ; Robin, A. ^{[5, 4, 6]} ; Jourdan, C. ^[4] ; Paula, R. R. ^[7] ; Pinheiro, R. C. ^[3] ; Guillemot, J. ^{[5, 4, 1]} ; Goncalves, J. L. M. ^[1] ; Bouillet, J-P ^{[5, 4, 1]}

Affiliation

^[1] Univ Sao Paulo, ESALQ, Forest Sci Dept, BR-13418900 Piracicaba, SP - Brazil

^[2] Univ Loraine, AgroParisTech, INRAE, UMR Silva, F-54000 Nancy - France

^[3] Sao Paulo State Univ UNESP, Sch Agr, BR-18610307 Botucatu, SP - Brazil

^[4] Univ Montpellier, Eco & Sols, CIRAD, INRA, IRD, Montpellier SupAgro, Montpellier - France

^[5] CIRAD, UMR Eco & Sols, F-34060 Montpellier - France

^[6] Univ Sao Paulo, ESALQ, Soil Sci Dept, BR-13418900 Piracicaba, SP - Brazil

^[7] UFES, Ctr Ciencias Agr & Engn, Alto Univ S-N, BR-29500000 Alegre, ES - Brazil

• Document type: Journal article
• Source: PLANT AND SOIL; v. 460, n. 1-2 JAN 2021.
• Web of Science Citations: 1

Abstract

Aims Belowground interactions are still poorly understood in mixed-species forests. We investigated the effects of soil fertility on belowground processes in mixed planted forests. Methods The dynamics and traits of Eucalyptus and Acacia mangium fine roots (diameter < 2 mm) in plantations with 50% of each species were studied in a randomized block design established in a nutrient depleted soil. Stands with NPK fertilization applied at planting (F+) were compared to unfertilized stands (F-). Results In the 0-15 cm soil layer, Eucalyptus root mass density (RMD) was higher than Acacia RMD by 50% in F+ and 10% in F-, considering both ages. At 34 months of age, Eucalyptus RMD was 94% higher near Acacia trees than near Eucalyptus trees in F-. In this layer, Eucalyptus specific root length (SRL) was 21% higher than Acacia SRL at 16 months of age and was 10% higher in F- than in F+ at 34 months of age. The cumulative Eucalyptus fine root length production between 16 and 34 months was 66% higher in F- than in F+ in the 0-1 m soil layer. Conclusions Fertilization increased the competition between species and led to a partial exclusion of Acacia fine roots from the nutrient-rich topsoil. Soil exploration by Eucalyptus roots in the vicinity of Acacia trees was higher in F- than in F+, which suggests that unfertilized trees benefited from facilitation through higher soil N availability and direct N transfer from Acacia trees. (AU)

• FAPESP's process: 10/16623-9 - Ecological intensification of eucalyptus plantations by association of nitrogen fixing leguminous tree species
• Grantee: José Leonardo de Moraes Gonçalves
• Support Opportunities: Research Projects - Thematic Grants