Search results for "carbon (C)"
showing 10 items of 156 documents
Le Priming Effect dans le sol : mécanismes, acteurs et conséquences sur les services écosystémiques dans un contexte de changement global
2022
The priming effect (PE) is a key mechanism contributing to the carbon balance of the soil ecosystem. Almost 100 years of research since its discovery in 1926 have led to a rich body of scientific publications to identify the drivers and mechanisms involved. A few review articles have summarised the acquired knowledge; the last major one was published in 2010. Since then, knowledge on the soil microbial communities involved in PE and in PE + C sequestration mechanisms has been considerably renewed.This article reviews current knowledge on soil PE to state to what extent new insights may improve our ability to understand and predict the evolution of soil C stocks. We propose a framework to un…
Synchronie entre l'offre et la demande dans le cycle des nutriments: apprendre des écosystèmes naturels pour construire des agrosystèmes durables
2023
Redesigning agrosystems with more ecological regulations can help feed a growing population, preserve soils for future productivity and reduce environmental impacts. However, guidelines for redesigning agrosystems from natural systems are limited. Reviewing the last knowledge of ecosystem functioning, we outlined four ecological systems synchronizing the supply of soluble nutrients by soil biota to fluctuating plant nutrient demand. This synchrony limits deficiencies and excesses of soluble nutrient, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. We detail how ecological systems promoting synchrony can be ins…
The second life of terrestrial and plastic carbon as nutritionally valuable food for aquatic consumers
2023
Primary production is the basis for energy and biomolecule flow in food webs. Nutritional importance of terrestrial and plastic carbon via mixotrophic algae to upper trophic level is poorly studied. We explored this question by analysing the contribution of osmo- and phagomixotrophic species in boreal lakes and used 13C-labelled materials and compound-specific isotopes to determine biochemical fate of carbon backbone of leaves, lignin–hemicellulose and polystyrene at four-trophic level experiment. Microbes prepared similar amounts of amino acids from leaves and lignin, but four times more membrane lipids from lignin than leaves, and much less from polystyrene. Mixotrophic algae (Cryptomonas…
Contributo per una visione contemporanea dell’azienda agricola: tra sostenibilità e sfide del mondo digitale
2023
Le sfide che l’umanità sta affrontando e da cui dipende la sopravvivenza del pianeta, il diffondersi nell’ambito dell’attività agricola di tecnologie digitali sempre più avanzate e la necessità di adottare un approccio sostenibile che preservi le risorse a tutela delle generazioni future hanno condotto l’azienda agricola a cambiare gradualmente volto. Questo libro mira a contribuire a un’aggiornata riflessione sul ruolo dell’imprenditore agricolo e dell’azienda da lui condotta, osservandone l’organizzazione e composizione alla luce delle regole che oggi la disciplinano e guardando alle innovazioni necessarie a garantire il raggiungimento dei pressanti obiettivi climatici e ambientali verso …
Integral functions of marine vertebrates in the ocean carbon cycle and climate change mitigation
2021
Summary In the last decade, the ocean has absorbed a quarter of the Earth’s greenhouse gas emissions through the carbon (C) cycle, a naturally occurring process. Aspects of the ocean C cycle are now being incorporated into climate change mitigation and adaptation plans. Currently, too little is known about marine vertebrate C functions for their inclusion in policies. Fortunately, marine vertebrate biology, behavior, and ecology through the lens of C and nutrient cycling and flux is an emerging area of research that is rich in existing data. This review uses literature and trusted data sources to describe marine vertebrate C interactions, provides quantification where possible, and highligh…
Integration of physically based distributed hydrological model with model of carbon and nitrogen cycle: Luquillo Critical Zone Observatory, Puerto Ri…
2015
The dynamics of carbon and nitrogen cycles, increasingly influenced by human activities, are the key to the functioning of ecosystems. These cycles are influenced by the composition of the substrate, availability of nitrogen, the population of microorganisms, and by environmental factors. Therefore, land management and use, climate change, and nitrogen deposition patterns influence the dynamics of these macronutrients at the landscape scale. In this work a physically based distributed hydrological model, the tRIBS model, is coupled with a process-based multi-compartment model of the biogeochemical cycle to simulate the dynamics of carbon and nitrogen (CN) in the Mameyes River basin, Puerto …
Effective conductivity in association with model structure and spatial inhomogeneity of polymer/carbon black composites
1996
The relationship between effective conductivity and cell structure of polyethylene/carbon composites as well as between effective conductivity and spatial distribution of carbon black are discussed. Following Yoshida's model both structures can, in a way, be said to be intermediate between the well known Maxwell-Garnett (MG) and Bruggeman (BR) limiting structures. Using TEM photographs on composites with various carbon blacks we have observed that the larger is Garncarek's inhomogeneity measure H of two-dimensional (2D) representative distribution of the carbon black, the smaller is the effective conductivity of the composite.
Distinct and diverse anaerobic bacterial communities in boreal lakes dominated by candidate division OD1
2012
Lakes have a central role in the carbon cycle of the boreal landscape. These systems typically stratify in summer and their hypolimnetic microbial communities influence burial of biogenic organic matter in sediments. The composition of bacterial communities in these suboxic habitats was studied by pyrosequencing of 16S rRNA amplicons from five lakes with variable dissolved organic carbon (DOC) concentrations. Bacterioplankton communities in the hypolimnetic waters were clearly different from the surface layer with candidate division OD1, Chlorobi and Bacteroidetes as dominant community members. Several operational taxonomic units (OTUs) affiliated with candidate division OD1 were abundant a…
The synergy between the CsPbBr3 nanoparticle surface and the organic ligand becomes manifest in a demanding carbon–carbon coupling reaction
2020
We demonstrate here the suitability of CsPbBr3nanoparticles as photosensitizers for a demanding photoredox catalytic homo- and cross-coupling of alkyl bromides at room temperature by merely using visible light and an electron donor, thanks to the cooperative action between the nanoparticle surface and organic capping. Fil: Rosa-Pardo, Ignacio. Instituto de Ciencia Molecular; España. Universidad de Valencia; España Fil: Casadevall, Carla. Barcelona Institute Of Science And Technology. Institut Català D'investigació Química.; España Fil: Schmidt, Luciana Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigac…
Factors influencing carbon decomposition of topsoils from the Brazilian Amazon Basin
1999
The influence of texture and local climate, especially precipitation, on C decomposition was evaluated in topsoils under forest and pastures at different sites located in the western, central, and eastern Brazilian Amazon Basin. Independent of the geographical location and vegetation cover, C decomposition was lower in topsoils of fine texture with a sand/clay ratio of less than 1, compared to topsoils of coarse a texture with a sand/clay ratio ranging from 2 to 8. In the former, the low sand/clay ratio appears to reduce C decomposition. In the latter, besides the effect of the high sand/clay ratio, the local climate, especially the annual precipitation, seems to play an important role in c…