Search results for " Organic carbon"
showing 10 items of 291 documents
SOILS WITH HIGH ORGANIC CARBON STORAGE CAPACITY IN DEPTH
2012
Most studies about soil organic carbon (OC) stock focus on the topsoil storage capacity, however, it has been proved that OC can reach relatively high values also in depth. The aim of this work was a preliminary investigation of the soil types with a high OC content in depth and the relationship with the main pedogenetic factors. The dataset was the 1,414 Italian National Soil Typologies (STU). The selected attributes were: mean value of OC in the superficial functional horizon (L1); weighted average value between 50 and 100 cm (L2) and under 100 cm (L3); WRB classification; main lithology, morphology and land-use. About 92% of typologies had more than 0.58% of OC in L1, about 30% in L2, an…
Differential response of benthic microbes and meiofauna to fish-farm disturbance in coastal sediments
2001
Bacterial and meiofaunal abundance and biomass and their response to the disturbance induced by fish-farm biodeposition were investigated from March to October 1997 on a monthly basis at two stations of the Gaeta Gulf (Tyrrhenian Sea, Mediterranean Sea). The biopolymeric fraction of the organic matter was characterized by high concentrations which was similar at both fish-farming-impacted and control stations. Similarly, bacteria accounted for a small fraction of the biopolymeric organic carbon (<1%), while the contribution due to auto-fluorescent cell biomass (i.e. prokaryotic and eukaryotic cells displaying auto-fluorescence) to the total biopolymeric carbon was quantitatively negligible …
Sedimentary record of anthropogenic contaminants (trace metals and PAHs) and organic matter in a Mediterranean coastal area (Gulf of Palermo, Italy)
2009
Abstract The Gulf of Palermo (Italy, Mediterranean Sea) is a contaminated coastal environment with a relatively high influx of unregulated industrial and domestic effluents. Two sediment box-cores were collected at water depths of 100 and 712 m. Samples were analysed for trace metals (As, Cu, Hg, Mn, Ni, Pb), total polycyclic aromatic hydrocarbons (ΣPAHs), organic carbon to total nitrogen (Corg/Ntot) ratios and organic carbon and nitrogen isotopic composition (δ13Corg and δ15Ntot). At the coastal site, trace metal and ΣPAH depth profiles show a clear upcore increase, indicating increasing contamination over the recent past. Concentrations of ΣPAHs, Hg, Pb, Cu, and As appear to be potentiall…
Ocean acidification effects on stable isotope signatures and trophic interactions of polychaete consumers and organic matter sources at a CO2 shallow…
2015
Abstract Stable carbon and nitrogen isotope analysis (SIA) was used to examine trophic interactions in a naturally acidified shallow coastal CO2 area in the Mediterranean Sea. SIA was helpful to determine the potential effects of ocean acidification (OA) on the interactions of organic matter sources and polychaete consumers, which appear to be tolerant to high pCO2. Mesoherbivore consumers, represented by three polychaete species, Platynereis dumerilii (Audouin and Milne Edwards, 1834) (Nereididae), Polyophthalmus pictus (Dujardin, 1839) (Opheliidae) and Syllis prolifera Krohn, 1852 (Syllidae), are abundant in the low pH conditions of the CO2 vents. Samples of consumers and potential organi…
Enzymatically hydrolyzable protein and carbohydrate sedimentary pools as indicators of the trophic state of detritus sink system: a case study in a M…
2003
In order to classify the trophic state of 'detritus sink' systems, instead of the conventional indicators based on inorganic nutrient availability and algal biomass and productivity in the water column, we utilized new biochemical descriptors based on the amount of sedimentary organic carbon and nitrogen potentially available to heterotrophic nutrition. We investigated spatial and temporal changes in microphytobenthic biomass, organic matter biochemical composition and enzymatically hydrolyzable protein and carbohydrate pools along a N-S transect in the Marsala lagoon (Mediterranean Sea, Italy) at three stations characterized by different hydrodynamic conditions and organic matter content i…
The effect of fish farming organic waste on food availability for bivalve molluscs (Gaeta Gulf, Central Tyrrhenian, MED): stable carbon isotopic anal…
2001
Stable carbon isotope (δ13C) analysis was used in a fish-farming impacted Mediterranean area (the Gulf of Gaeta, Central Tyrrhenian) to determine the predominant carbon sources available to bivalve molluscs cultivated around fish cages. Wether the organic matter generated by fish farming was taken up by the bivalve molluscs was also investigated. Stable carbon isotope values were measured in the particulate organic carbon (POC) of samples from potential organic matter sources such as fish-pelleted feed, mollusc faecal waste and bivalve flesh. The sources of organic matter affecting the study area water column and benthic communities appeared to be terrigenous-continental, autochthonous (phy…
La denitrificazione biologica delle acque di falda: studio di tre differenti substrati organici
2015
L’uso massiccio di fertilizzanti contenenti azoto è causa dei fenomeni di inquinamento diffuso delle acque di falda. In tale ottica, notevole interesse hanno recentemente riscosso i trattamenti biologici in situ, in grado di promuovere la denitrificazione delle acque di falda mediante la realizzazione di interventi che coniugano efficacia di rimozione e costi relativamente contenuti. Nella nota si riportano i risultati di una ricerca sul processo di denitrificazione eterotrofa, condotta utilizzando come fonte di carbonio tre materiali convenzionalmente considerati di scarto: corteccia di pino, sughero e sansa di olive. Lo studio è stato suddiviso in due fasi: la prima condotta in modalità b…
The organic carbon derived from sewage sludge as a key parameter determining the fate of trace metals.
2007
8 pages; International audience; In a sandy agricultural soil of south-west of France, continuously cultivated with maize and amended with sewage-sludge over 20 years, the behavior of three trace metals (Cu, Pb, and Zn) was studied during the sludge applications (1974-1993) and after its cessation (1993-1998). Using the delta13C analysis, the dynamics of different sources of organic matter were followed in order to elucidate the influence of the sludge-derived organic matter on the fate of trace metals in the soil and its particle size fractions. This study revealed that sludge-derived organic matter contributed to the formation of macroaggregates through the binding of preexisting microagg…
Modelling soil carbon fate under erosion process in vineyard
2017
Soil erosion processes in vineyards beyond water runoff and sediment transport have a strong effect on soil organic carbon loss (SOC) and redistribution along the slope. The variation of SOC across the landscape determines a difference in soil fertility and vine productivity. The aim of this research was to study erosion of a Mediterranean vineyard, develop an approach to estimate the SOC loss, correlate the vines vigor with sediment and carbon erosion. The study was carried out in a Sicilian (Italy) vineyard, planted in 2011. Along the slope, six pedons were studied by digging 6 pits up to 60cm depth. Soil was sampled in each pedon every 10cm and SOC was analyzed. Soil erosion, detachment …
Cover Crop Impact on Soil Organic Carbon, Nitrogen Dynamics and Microbial Diversity in a Mediterranean Semiarid Vineyard
2020
Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season