Abstract
Abstract. Lipid tracers including fatty acids, hydroxyacids, n-alkanols, sterols and triterpenoids were used to determine the origin and fate of suspended particulate organic matter (POM) collected in the Rhône River (France). This seasonal survey (April 2011 to May 2013) revealed a year-round strong terrestrial higher-plant contribution to the particulate organic matter (POM), with significant algal inputs observed in March and attributed to phytoplanktonic blooms likely dominated by diatoms. Major terrigenous contributors to our samples are gymnosperms, and more precisely their roots and stems, as evidenced by the presence of high proportions of ω-hydroxydocosanoic acid (a suberin biomarker). The high amounts of coprostanol detected clearly show that the Rhône River is significantly affected by sewage waters. Specific sterol degradation products were quantified and used to assess the part of biotic and abiotic degradation of POM within the river. Higher-plant-derived organic matter appears to be mainly affected by photo-oxidation and autoxidation (free radical oxidation), while organic matter of mammal or human origin, evidenced by the presence of coprostanol, is clearly more prone to bacterial degradation. Despite the involvement of an intense autoxidation-inducing homolytic cleavage of peroxy bonds, a significant proportion of hydroperoxides is still intact in higher plant debris. These compounds could affect the degradation of terrestrial material by inducing an intense autoxidation upon its arrival at sea.
Subject
Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics
Reference84 articles.
1. AGRESTE: En Provence-Alpes-Côte d'Azur, la forêt est sous-exploitée (Rapport du Ministère de l'agriculture, de l'alimentation, de la pêche, de la ruralité et de l'aménagement du territoire), 2011.
2. Amelung, W., Brodowski, S., Sandhage-Hofmann, A., and Bol, R.: Chapter 6 Combining Biomarker with Stable Isotope Analyses for Assessing the Transformation and Turnover of Soil Organic Matter, in: Advances in Agronomy, edited by: Sparks D. L., Academic Press, 155–250, 2008.
3. Aminot, A. and Kérouel, R.: Dosage automatique des nutriments dans les eaux marines: méthodes en flux continu (Editions Quae), 2007.
4. Atlas, R. M. and Bartha, R.: Hydrocarbon Biodegradation and Oil Spill Bioremediation, in: Advances in Microbial Ecology, edited by: Marshall K. C., Springer US, 287–338, 1992.
5. Bourbonniere, R. A. and Meyers, P. A.: Sedimentary geolipid records of historical changes in the watersheds and productivities of Lakes Ontario and Erie, Limnol. Oceanogr., 41, 352–359, 1996.
Cited by
19 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献