Search results for " Ecosystem"
showing 10 items of 633 documents
Valorization of Marine Waste: Use of Industrial By-Products and Beach Wrack Towards the Production of High Added-Value Products
2021
Biomass is defined as organic matter from living organisms represented in all kingdoms. It is recognized to be an excellent source of proteins, polysaccharides and lipids and, as such, embodies a tailored feedstock for new products and processes to apply in green industries. The industrial processes focused on the valorization of terrestrial biomass are well established, but marine sources still represent an untapped resource. Oceans and seas occupy over 70% of the Earth’s surface and are used intensively in worldwide economies through the fishery industry, as logistical routes, for mining ores and exploitation of fossil fuels, among others. All these activities produce waste. The other sou…
Risk Assessment of Toxicants to Pelagic Food-Webs: A Simulation Study
1991
For a generalized mathematical model of the pelagic compartment of a lake ecosystem we show that a small variance in input parameters may result in a large variance in predicted biomasses. Since input parameters for this kind of models always show a great variance, we conclude that deterministic prediction of biomass-trajectories is rather useless and demonstrate how stochastic analysis of the model may lead to a helpful risk analysis.
Gobio Genus Species Integrated Management System – Târnava Rivers Study Case (Transylvania, Romania)
2019
Abstract The lotic habitats quality indicative congeners species Gobio gobio, Gobio kessleri and Gobio albipinnatus populations’ dynamic in time (2004-2019) and space revealed a decreasing trend in these rivers ecological status. The ADONIS:CE tool has been used to build a backing management system model, based on these indicative fish species habitat needs, indicators for favourable conservation status, pressures and threats. This management system implementation in the field will favour the amelioration of lotic habitats and the ecological status recovering of two of the local fish species of conservative interest (G. kessleri and G. albipinnatus).
Flash-Floods Influence Macroinvertebrate Communities Distribution in Lotic Ecosystems
2019
Abstract Stream dwelling invertebrate populations are facing an ample array of stressors including the habitat imbalance caused by important floods. In this research we used a novel way to estimate the impact of floods upon the substrate, by utilising a remote variable named “flash-flood potential” (FFP), which accounts for the site slope and the average slope of the upstream catchment. The results showed that certain groups are sensitive to the influence of the FFP whereas other are not. We propose this remote variable as a surrogate for assessing stress imposed by floods and sediment scouring for lotic macroinvertebrates.
Species richness-standing crop relationship in stream bryophyte communities: patterns across multiple scales
2001
Summary 1 We tested for a unimodal (‘hump-backed’) relationship between species richness and standing crop at various spatial scales in stream bryophyte communities. Bryophyte species and their biomasses were determined from 20 to 25 quadrats in eight river and six stream sites in northern Finland. 2 Regression analyses revealed a quadratic relationship between richness and biomass in only two of the river sites and a positive correlation in one other. A quadratic relationship was detected in three stream sites and richness increased linearly with biomass in another. 3 We also tested for the hump-shaped pattern across individual stream boulders, representing an elevational gradient from con…
Evidence de l'adaptation des communautés microbiennes sédimentaires de rivière à la minéralisation du diuron: influence du ruissellement et de l'éros…
2010
International audience; Purpose Surface runoff and erosion are major drivers of pesticide transport from soils to rivers draining vineyard watersheds. A recent study showed that applications of diuron on vineyards and diuron dispersal could lead to microbial adaptation to diuron biodegradation from treated soils to the receiving hydrosystem. Given the limited knowledge on microbial adaptation to pesticide degradation in aquatic environments, we conducted a microcosm study designed to assess the impact of runoff and erosion processes on the adaptation of riverine-sediment microbial communities to diuron mineralization. Materials and methods The experimental laboratory set-up consisted in aqu…
Salinity and Bacterial Diversity: To What Extent Does the Concentration of Salt Affect the Bacterial Community in a Saline Soil?
2014
In this study, the evaluation of soil characteristics was coupled with a pyrosequencing analysis of the V2-V3 16S rRNA gene region in order to investigate the bacterial community structure and diversity in the A horizon of a natural saline soil located in Sicily (Italy). The main aim of the research was to assess the organisation and diversity of microbial taxa using a spatial scale that revealed physical and chemical heterogeneity of the habitat under investigation. The results provided information on the type of distribution of different bacterial groups as a function of spatial gradients of soil salinity and pH. The analysis of bacterial 16S rRNA showed differences in bacterial compositi…
Improved Salmonella recovery from moderate to highly polluted waters.
1982
A new enrichment procedure for the recovery of salmonellas from aquatic environments is proposed. It has been tested in a eutrophic lake showing moderate to high faecal contamination levels (the Albufera lake near Valencia, Spain), and in effluents coming into a wastewater treatment plant. The new method consists of the addition of sodium novobiocin to a modification of Rappaport's medium (R10/43°C). The new medium (NR10/43°C) allows a better recovery of salmonellas from water than selenite broth.
SEA WATER TEMPERATURE RECORDS GATHERED DURING EXPERIMENTAL BOTTOM TRAWL SURVEYS IN THE STRAIT OF SICILY (MEDITERRANEAN SEA)
2009
Depth and sea water temperature values recorded by a Minilog system during several bottom trawl surveys carried out in the Strait of Sicily (Central Mediterranean Sea) in spring (MEDITS) and late summer (GRUND), were analyzed by using an ad hoc developed software (MiSeAT). Depth and temperature profiles were analyzed for each haul. Three sea water temperature (t°C) values were considered: the upper and lower water layers temperature, and the difference between them. Mean values by depth stratum and the corresponding standard deviations were estimated for the three parameters, then compared between the two seasons. Haul parameters recorded during the more heterogeneous GRUND surveys (due to …
PLUMBAGO AURICULATA LAM. (Plumbaginaceae) IN SICILIA OCCIDENTALE: NUOVI DATI SULLA SUA DIFFUSIONE COME ESOTICA CASUALE
2017
Plumbago auriculata Lam. (Plumbaginaceae) in western Sicily: new data on its spread as casual alien. In questa nota si fornisce un quadro aggiornato sui casi di naturalizzazione di Plumbago auriculata Lam. (Plumbaginaceae) nella Sicilia occidentale e sul suo status invasivo a livello nazionale ed internazionale. Questa xenofita viene segnalata per la prima volta in diverse aree delle province di Agrigento, Palermo e Trapani, dopo essere stata segnalata per la prima volta presso l'isola di Linosa, nell'arcipelago delle Pelagie.