The manipulation of organic residues affects tree growth and heterotrophic CO2 efflux inatropical Eucalyptus plantation
Fast-growing plantationsareincreasinglybeingestablishedontropicalsoils,wherefertilityislargely supported bysoilorganicmatter(SOM)andwheredifferentmanagementoptionsofharvestorganicres- idues isthoughttoimpactthelong-termsustainabilityoftheseplantations.Theobjectivesofthisstudy were: (1)toquantifytheeffectofcontrastingmethodsoforganicresiduemanagementontreegrowth and soilCO2 effluxes inthefirst2yearsafterplantingand(2)toevaluatetheimpactoforganicresidue manipulations onthemineralizationofsoilorganicmatteroverthelengthoftheexperiment.Threetreat- ments weresetupin0.125haplotsandreplicatedinthreeblocksattheharvestingofaCongolese Euca-lyptus stand, resultinginanabovegroundorganicresiduemassrangingfrom0to6.3kgm_2. The mineralization ofSOMwasdeducedineachtreatmentbypartitioningsourcesofsoilCO2 effluxes using decomposition experimentsandbyupscalingspecificrootrespiration.SoilCO2 effluxes weregreatly affected byseasonsandorganicresiduemanipulation,althoughtherewerenosignificantchangesintop- soil watercontentandtopsoiltemperatureovermostofthestudyperiod.Abovegroundorganicresidue was thefirstcontributortosoilCO2 efflux inthetwotreatmentswithalitterlayer.Organicresidueman- agement didnotsignificantlyinfluencethemineralizationofSOMinourstudy,probablyduetothelow quality of Eucalyptus litter, ortothehypotheticallackofdissolvedorganiccarbontransfersfromlitterto soil. AstrongrelationshipwasfoundbetweencumulativeheterotrophicCO2 efflux andtreegrowth,sup- porting thehypothesisthattheearlygrowthof Eucalyptus trees inasandytropicalsoilislargelydepen- dent onthenutrientsreleasedbythedecompositionoforganicresidues.
| Main Authors: | , , , , , , , |
|---|---|
| Format: | article biblioteca |
| Language: | eng |
| Published: |
Elsevier
|
| Subjects: | K10 - Production forestière, F62 - Physiologie végétale - Croissance et développement, P33 - Chimie et physique du sol, Eucalyptus, résidu de récolte, croissance, respiration du sol, minéralisation, matière organique du sol, http://aims.fao.org/aos/agrovoc/c_2683, http://aims.fao.org/aos/agrovoc/c_16118, http://aims.fao.org/aos/agrovoc/c_3394, http://aims.fao.org/aos/agrovoc/c_33553, http://aims.fao.org/aos/agrovoc/c_15999, http://aims.fao.org/aos/agrovoc/c_35657, http://aims.fao.org/aos/agrovoc/c_1811, |
| Online Access: | http://agritrop.cirad.fr/569061/ http://agritrop.cirad.fr/569061/1/document_569061.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Fast-growing plantationsareincreasinglybeingestablishedontropicalsoils,wherefertilityislargely supported bysoilorganicmatter(SOM)andwheredifferentmanagementoptionsofharvestorganicres- idues isthoughttoimpactthelong-termsustainabilityoftheseplantations.Theobjectivesofthisstudy were: (1)toquantifytheeffectofcontrastingmethodsoforganicresiduemanagementontreegrowth and soilCO2 effluxes inthefirst2yearsafterplantingand(2)toevaluatetheimpactoforganicresidue manipulations onthemineralizationofsoilorganicmatteroverthelengthoftheexperiment.Threetreat- ments weresetupin0.125haplotsandreplicatedinthreeblocksattheharvestingofaCongolese Euca-lyptus stand, resultinginanabovegroundorganicresiduemassrangingfrom0to6.3kgm_2. The mineralization ofSOMwasdeducedineachtreatmentbypartitioningsourcesofsoilCO2 effluxes using decomposition experimentsandbyupscalingspecificrootrespiration.SoilCO2 effluxes weregreatly affected byseasonsandorganicresiduemanipulation,althoughtherewerenosignificantchangesintop- soil watercontentandtopsoiltemperatureovermostofthestudyperiod.Abovegroundorganicresidue was thefirstcontributortosoilCO2 efflux inthetwotreatmentswithalitterlayer.Organicresidueman- agement didnotsignificantlyinfluencethemineralizationofSOMinourstudy,probablyduetothelow quality of Eucalyptus litter, ortothehypotheticallackofdissolvedorganiccarbontransfersfromlitterto soil. AstrongrelationshipwasfoundbetweencumulativeheterotrophicCO2 efflux andtreegrowth,sup- porting thehypothesisthattheearlygrowthof Eucalyptus trees inasandytropicalsoilislargelydepen- dent onthenutrientsreleasedbythedecompositionoforganicresidues. |
|---|