Degradation of softwood [14C lignin] lignocelluloses and its relation to the formation of humic substances in river and pond environments
✍ Scribed by Eliane Fustec; Eric Chauvet; Gilbert Gas; Daniel Lacaze; Michèle Escautier
- Publisher
- Springer
- Year
- 1988
- Tongue
- English
- Weight
- 597 KB
- Volume
- 159
- Category
- Article
- ISSN
- 1573-5141
No coin nor oath required. For personal study only.
✦ Synopsis
The fate of lignin in water and sediment of the Garonne river (France) and of a pond in its floodplain was examined using specifically labeled [4C-lignin] lignocelluloses. No significant differences appeared in the mineralization rate of alder, poplar or willow [' 4 C-lignin] in running water samples. Conversion of total radioactivity to 14 CO 2 ranged between 18.7%o and 24.4% after 120 days of incubation. Degree of 14C-labeled lignin mineralization in standing water and sediments was clearly lower, especially in submerged sediments, and was correlated with oxygen supply. After 60 days of incubation 3.3% to 7.9% of the 4C-labeled lignin was recovered in water samples as dissolved organic carbon originating from microbial metabolism. In water extracts from sediment the percentage of dissolved organic 14C was only 0.4% to 1.3% of the applied activity. In the humic fraction extracted from sediments it did not exceed 4.4%07 which was much lower than in soils. No significant difference appeared between river and pond conditions for humic substances formation.