کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5162965 1379763 2006 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Organic matter and lipids in sediments of Lake Bled (NW Slovenia): Source and effect of anoxic and oxic depositional regimes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Organic matter and lipids in sediments of Lake Bled (NW Slovenia): Source and effect of anoxic and oxic depositional regimes
چکیده انگلیسی
Sources of organic matter (OM) and lipids were assessed and factors affecting OM degradation were studied for two sediment cores representing distinct depositional regimes (i.e., the oscillating oxic to suboxic/anoxic western basin and oxic Zaka Bay) for eutrophic Lake Bled, NW Slovenia. Lower surface organic carbon (OC) concentration was determined in the western basin than for Zaka Bay sediments (5.1 vs. 5.4 wt% dry sediment, respectively), but one order of magnitude greater total lipid concentration was observed in the former. Also, there was a higher proportion of autochthonous OM in the western basin (∼77% vs. ∼66%) on the basis of atomic C/N ratios. Lipid-based origin assessment suggested a similar contribution of autochthonous OM in the western basin (64-77%), but a lower one in Zaka Bay (<50%). It seems that redox potential is the main factor governing OM degradation in the western basin. In contrast, a contribution from more refractory terrestrial OM, via the surface inflow in Zaka Bay, and higher sedimentation rates may surpass redox effects in Zaka Bay. Overall, oxygen may play a more important role in degradation of the more labile pool (i.e., lipids) than bulk OM. Higher apparent degradation rate constants (k′) for lipids also suggested a greater lability than for OC, while respective k′ values were higher in the oxic than anoxic environment.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Geochemistry - Volume 37, Issue 12, December 2006, Pages 1664-1679
نویسندگان
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