Carbon fluxes and allocation pattern in an apple orchard

Zanotelli, Damiano (2012) Carbon fluxes and allocation pattern in an apple orchard, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Colture arboree ed agrosistemi forestali ornamentali e paesaggistici, 24 Ciclo. DOI 10.6092/unibo/amsdottorato/4889.
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Abstract

Carbon fluxes and allocation pattern, and their relationship with the main environmental and physiological parameters, were studied in an apple orchard for one year (2010). I combined three widely used methods: eddy covariance, soil respiration and biometric measurements, and I applied a measurement protocol allowing a cross-check between C fluxes estimated using different methods. I attributed NPP components to standing biomass increment, detritus cycle and lateral export. The influence of environmental and physiological parameters on NEE, GPP and Reco was analyzed with a multiple regression model approach. I found that both NEP and GPP of the apple orchard were of similar magnitude to those of forests growing in similar climate conditions, while large differences occurred in the allocation pattern and in the fate of produced biomass. Apple production accounted for 49% of annual NPP, organic material (leaves, fine root litter, pruned wood and early fruit drop) contributing to detritus cycle was 46%, and only 5% went to standing biomass increment. The carbon use efficiency (CUE), with an annual average of 0.68 ± 0.10, was higher than the previously suggested constant values of 0.47-0.50. Light and leaf area index had the strongest influence on both NEE and GPP. On a diurnal basis, NEE and GPP reached their peak approximately at noon, while they appeared to be limited by high values of VPD and air temperature in the afternoon. The proposed models can be used to explain and simulate current relations between carbon fluxes and environmental parameters at daily and yearly time scale. On average, the annual NEP balanced the carbon annually exported with the harvested apples. These data support the hypothesis of a minimal or null impact of the apple orchard ecosystem on net C emission to the atmosphere.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Zanotelli, Damiano
Supervisore
Co-supervisore
Dottorato di ricerca
Scuola di dottorato
Scienze agrarie
Ciclo
24
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
Apple orchard, Carbon fluxes, Carbon Use Efficiency, Allocation pattern, Environmental drivers
URN:NBN
DOI
10.6092/unibo/amsdottorato/4889
Data di discussione
16 Aprile 2012
URI

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