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Studying the functioning of benthic hotspot and coldspot ecosystems in the canadian Arctic

出版	Université du Québec à Rimouski, 2012
URL	http://books.google.com.hk/books?id=_drcoQEACAAJ&hl=&source=gbs_api

註釋Ln chapitre 1 of my thesis I asked how the spring-to-summer transition influences benthic carbon remineralisation and its potential determining factors, food supply and infaunal biomass, in the southeastern Beaufort Sea. I found that benthic remineralisation and food supply patterns vary on the seasonal time scale, although infaunal biomass and sediment Chl a concentration does not. In both spring and summer, sediment Chl a concentration is the prime determinant of benthic carbon remineralisation, but other factors have a significant secondary influence, such as water depth (in spring) and infaunal biomass (in summer). These findings indicate the importance of the combined and dynamic effects of food supply and benthic community patterns on the carbon remineralisation. My second objective was to determine the influence of biotic and abiotic environmental parameters, that vary on different time scales, on the spatial variation of multiple benthic remineralisation fluxes (chapitre 2) . Multivariate analysis of flux data showed that the commonly used proxy (oxygen flux) does not explain overall variation in benthic remineralisation. I tested the influence of the following environmental parameters on benthic fluxes : vertical flux of particulate organic carbon, sediment surface Chl a (both short-term), porosity, surface manganese and iron concentration, bottom water oxygen (all long-term), phaeopigments (intermediate-term influence) and δl3C org (terres trial influence). The overall spatial distribution of fluxes can be best explained by sediment Chl a, phaeopigments, δ13C org, surficial manganese and bottom-water oxygen concentration. This indicates that environmental parameters of short time variation are most important for