Search results for "ORGANIC MATTER"
showing 10 items of 577 documents
Ontogenetic δ15N Trends and Multidecadal Variability in Shells of the Bivalve Mollusk, Arctica islandica
2021
Bulk stable nitrogen isotope values of the carbonate-bound organic matrix in bivalve shells (δ15NCBOM) are increasingly used to assess past food web dynamics, track anthropogenic nitrogen pollution and reconstruct hydrographic changes. However, it remains unresolved if the δ15NCBOM values are also affected by directed ontogenetic trends which can bias ecological and environmental interpretations. This very aspect is tested here with modern and fossil specimens of the long-lived ocean quahog, Arctica islandica, collected from different sites and water depths in the NE Atlantic Ocean. As demonstrated, δ15NCBOM values from the long chronologies show a general decrease through lifetime by −0.00…
Environmental Organic Photochemistry: Advances and Perspectives
2013
This review is a survey of recent advances in environment related aspects of organic photochemistry. Besides presenting gen- eral concepts, the manuscript is mainly focused on the photoreactivity of natural organic matter, and on the photochemistry of anthropo- genic substances under natural light irradiation.
Effects of arbuscular mycorrhizal symbiosis on the nitrogen uptake of three durum wheat genotypes from two different organic sources
2012
Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in the black crusts of Sicilian stone monuments: distribution and sources
2004
Polycyclic Aromatic Hydrocarbons are a family of compounds with known carcinogenic potential; their properties of lipophilicity, low water solubility and adsorption to particles and sediments make them a potentially dangerous group of chemicals and a threat to the environment and its bio-resources. The concentrations of total Polycyclic Aromatic Hydrocarbons (PAHs) and 19 individual compounds in 8 black crusts sampled from historical building of Palermo (Italy) were analyzed, by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. PAH concentrations ranged from 78 to 9798 g/Kg of dry matrix. The resulting distributions and molecular ratios of specific compo…
Priming effect increases with depth in a boreal forest soil
2016
Abstract Climate warming increases labile carbon (C) inputs to soil through increased photosynthesis and C allocation belowground. This could counterintuitively lead to losses of soil C via priming effects (PE): the stimulation of soil organic matter (SOM) decomposition caused by labile C addition. Systematic quantification of PEs in different ecosystems is needed. We measured PEs of free-living soil microbes in different layers of a boreal forest soil, and found that the relative magnitude of the PE increased with soil depth. The relationship between relative PE and the added glucose amount also depended on the soil layer. Our results indicate that the decomposition of SOM in deeper soil l…
KOSMOS 2017 Peru Side Experiment: nutrients, phytoplankton abundances, enzyme rates, photophysiology
2022
This data was collected during an short-term incubation experiment in March 2017 that investigated the response of a surface plankton community to upwelling. This experiment was carried in the framework of the SFB754-funded KOSMOS mesocosm study that took place in La Punta, Callao, Peru between February-April 2017. A total of six different treatments were used to disentangle chemical and biological characteristics of deep water that influence surface plankton blooms: 2 different deep water sources with different nutrient concentrations; 3 treatments to distinguish the effects of inorganic nutrients, organic nutrients and deep water microbial populations. Measured variables include inorganic…
The effect of iron on the biodegradation of natural dissolved organic matter
2016
Iron (Fe) may alter the biodegradation of dissolved organic matter (DOM), by interacting with DOM, phosphorus (P), and microbes. We isolated DOM and a bacterial community from boreal lake water and examined bacterial growth on DOM in laboratory experiments. Fe was introduced either together with DOM (DOM-Fe) or into bacterial suspension, which led to the formation of insoluble Fe precipitates on bacterial surfaces (Fe coating). In the latter case, the density of planktonic bacteria was an order of magnitude lower than that in the corresponding treatment without introduced Fe. The association of Fe with DOM decreased bacterial growth, respiration, and growth efficiency compared with DOM alon…
Straw uses trade-off only after soil organic carbon steady-state
2018
Soil organic matter (SOM) is the key for a healthy soil and a relevant property to achieve the sustainability on soil management. However, soils are still net exporters of organic matter. One example is the use of wheat straw residue for industrial and energy applications, which has gained attention in the last years. The offfarm use of this abundant and low cost resource should follow sustainability criteria to avoid soil degradation and SOM losses. Straw residue incorporation is recognized as a recommended management practice to control erosion and mitigate CO2 emissions by increasing SOM. The goal of this work was: i) to evaluate the steady-state carbon (C) level in relation to C input a…
Carbon stocks in a 50‑year‑oldEucalyptus camaldulensisstand in Sicily, Italy
2015
Eucalyptus stands in semi-arid areas may contribute to enhance carbon (C) stocks in both biomass and soil. However, the limited information available is mainly focused on short-rotation plantations. In this study, the above- and below-ground C pools in five 50-year-old Eucalyptus camaldulensis Dehnh. stands planted on Miocenic evaporitic deposits in Sicily, Italy, with a xeric and thermic pedoclimate, were measured. Above-ground biomass was determined by partitioning and weighing branches, stem and leaves. Below-ground C pools included the determination of litter, root biomass, and soil organic and inorganic C. In terms of the above-ground biomass, the E. camaldulensis stand accumulated on …