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Comparative study of humic acids of the mound of a wood-feeding termite and of the litter directly below in the Amazon river delta

Richard, Jean-François and Ait Baddi, Ghita and Costa, Carlos and Guiresse, Agnès Maritchù and Kaemmerer, Michel and Hafidi, Mohamed and Revel, Jean-Claude Comparative study of humic acids of the mound of a wood-feeding termite and of the litter directly below in the Amazon river delta. (2006) Chemistry and Ecology, 22 (3). 201-209. ISSN 0275-7540

(Document in English)

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Official URL: http://dx.doi.org/10.1080/02757540600658807


In order to determine the role of termites in the recycling of organic matter and in humification processes, organic matter from the mound of a wood-feeding termite (Nasutitermes sp.) and from the litter directly below has been studied in secondary forest on the campus of Belem University, in Brazil. The carbon content was slightly lower in the litter ( just beneath the mound) than in the mound, but nitrogen was much more abundant in the mound. As a consequence, the C/N ratio of fragmented litter total organic matter is very high, which shows that the humification process is not complete. Therefore, plant debris seemed to be more degraded in the mound than in the litter, indicating a humification gradient from mound to litter. Humic acid extracted from the mound and from the litterwas compared by using elemental, E4/E6 ratio, spectroscopic (FTIR) analyses, and Sephadex gel chromatography. First, humic acids were more abundant in the mound than in the litter, showing that humification processes were more advanced in the mound than in the litter. Gel-permeation chromatography showed that the humic acids of the mound contained more low-molecular-weight fractions than those of the litter. In addition, the results of infrared spectra, E4/E6 ratio and elemental composition can confirm the fulvic character of mound material and the humic character of litter material. Therefore, the plant debris seems to follow two different humification pathways in the two environments, as long as the mound is alive.

Item Type:Article
Additional Information:Thanks to Taylor and Francis editor. The definitive version is available at http://www.tandfonline.com/ The original PDF of the article can be found at http://www.tandfonline.com/doi/abs/10.1080/02757540600658807
HAL Id:hal-01517382
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Other partners > University of Cadi Ayyad - UCAM (MOROCCO)
Other partners > Universidade Federal do Pará - UFPA (BRAZIL)
Laboratory name:
Deposited On:03 May 2017 08:32

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