Impact du mélange robinier/peuplier sur l'assimilation et l'allocation d'azote de peupliers cultivés en plantation à courte rotation

Abstract : The short rotation coppices (SRC), often based on marginal sites, are being considered actually as a source of biomass. The soil nitrogen (N) is an essential element for nutrition and development of trees in these planting systems. At Saint-Cyr-en-Val (Center of France), the effect of the combination of two non-nitrogen-fixing species (Populus euramericana) / nitrogenfixing species (Robinia pseudoacacia) on the productivity of two-year-old poplar has been studied, and a 15N labeling of soil has been realized to follow N absorption by the two species. Isotopic composition of 15N of labeled and unlabeled tree organs has been analyzed by mass spectrometry. The delta15N/1000 of unlabelled plants was about 2.86/1000 for poplar and about 0.27/1000 for black locust. The negative value of delta15N of black locust was close to the one of atmosphere. Decreased delta15N of poplar in mixed coppice suggests that N allocation from black locust toward poplar occurred. Carbon and N accumulation in poplar of mixed coppice tended to increase compared to the ones of pure coppices. Analysis of 15N of labeled plants showed that poplar in mixed coppices was more N demanding with respect to soil N. The amount of N derived from atmospheric fixation was measured using the method of 15N isotope dilution: 77.3% mixed (50P: 50R) and 73.6% in pure coppice (100R: 0P).
Document type :
Master thesis
File URL :
http://docnum.univ-lorraine.fr/prive/BUS_M_2013_FARJAD_MAHSA.pdf
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https://hal.univ-lorraine.fr/hal-01778958
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Submitted on : Thursday, April 26, 2018 - 10:37:35 AM
Last modification on : Tuesday, July 23, 2019 - 4:00:33 PM

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Mahsa Farjad. Impact du mélange robinier/peuplier sur l'assimilation et l'allocation d'azote de peupliers cultivés en plantation à courte rotation. Sciences de l'environnement. 2013. ⟨hal-01778958⟩

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