Annals of Botany 91: 879-892, 2003
© 2003 Annals of Botany Company
Nutrient Dynamics throughout the Rotation of Eucalyptus Clonal Stands in Congo
1 CIRAD-Forêt/UR2PI, TA 10/C, 34398 Montpellier Cedex 5, France, 2 INRA, Biogéochimie des écosystèmes forestiers, 54280 Seichamps, France and 3 UR2PI, BP 1264, Pointe-Noire, République du Congo
* For correspondence at: CIRAD-Forêt/USP-ESALQ, IPEF, Av. Pádua Dias 11, Caixa Postal 530, CEP 13·400-970, Piracicaba-SP, Brazil. E-mail: laclau{at}cirad fr
Received: 15 November 2002; Returned for revision: 2 January 2003 ; Accepted: 21 February 2003
The dynamics of the main nutrient fluxes of the biological cycle were quantified in a clonal Eucalyptus plantation throughout the whole planted crop rotation: current annual requirements of nutrients, uptake from the soil, internal translocations within trees, return to soil (litterfall and crown leaching) and decomposition in the forest floor. As reported for other species, two growth periods were identified in these short-rotation plantations: (1) a juvenile phase up to canopy closure, during which the uptake of nutrients from the soil reserves supplied most of the current requirements; and (2) a second phase up to harvest, characterized by intense nutrient recycling processes. Internal translocation within trees supplied about 30 % of the annual requirements of N and P from 2 years of age onwards, and about 50 % of the K requirement. The mineralization of large amounts of organic matter returned to the soil with litterfall during stand development represented a key process providing nutrients to the stand at the end of the rotation. The importance of the recycling processes was clearly shown by the small amounts of nutrients permanently immobilized in the ligneous components of trees, compared with the total requirements accumulated over the stand rotation which were two to four times higher. Small pools of nutrients circulating quickly in the ecosystem made it possible to produce high amounts of biomass in poor soils. The sustainability of these plantations will require fertilizer inputs that match the changes in soil fertility over successive rotations, mainly linked to the dynamics of organic matter in this tropical soil.
Key words: Biomass, nutrient content, dynamics, Eucalyptus, eucalypt, plantation, Congo, Africa.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J.-P. Laclau, J. C.R. Almeida, J. L. M. Goncalves, L. Saint-Andre, M. Ventura, J. Ranger, R. M. Moreira, and Y. Nouvellon Influence of nitrogen and potassium fertilization on leaf lifespan and allocation of above-ground growth in Eucalyptus plantations Tree Physiol, January 1, 2009; 29(1): 111 - 124. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-P. LACLAU, F. TOUTAIN, A. T. M'BOU, M. ARNAUD, R. JOFFRE, and J. RANGER The Function of the Superficial Root Mat in the Biogeochemical Cycles of Nutrients in Congolese Eucalyptus Plantations Ann. Bot., March 1, 2004; 93(3): 249 - 261. [Abstract] [Full Text] [PDF]
|
|