This contribution examines various flow measures based on analysis of 41 quantified models of trophic interactions in aquatic ecosystems. System productivity/biomass ratio is shown to relate to ecosystem maturity and to the degree of cycling in the systems. Distinct patterns or clusters are observed for different types of resource systems with respect to average path lengths and residence times...

Italy is recognized as one of the prominent hot spot areas for plant diversity at regional and global scale, hosting a rich range of ecosystems and habitat types. This is especially true considering aquatic habitats, which represent a major portion of the total water surfaces in the Mediterranean region. Nevertheless, only a scant attention was paid to clarify the species richness of aquatic pl...

The study of planktonic ecosystems is important as they make up the bottom trophic levels of aquatic food webs. We study a closed nutrient-phytoplankton-zooplankton (NPZ) model that includes size structure in the juvenile zooplankton. The closed nature of the system allows the formulation of a conservation law of biomass that governs the system. The model consists of a system of a nonlinear ord...

Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather th...

Aquatic insects contribute significantly to freshwater ecosystems, forming food for many organisms, particularly in the food webs associated with wetland environments. Many fishes, amphibians, shorebirds, waterfowl, and other animals forage heavily on both the aquatic and terrestrial stages of aquatic insects, which are essential to their survival. It is estimated that about 3 % of the total in...

Periphytic algae are important components of aquatic ecosystems. However, the factors driving periphyton species richness variation remain largely unexplored. Here, we used data from a subtropical floodplain (Upper Paraná River floodplain, Brazil) to quantify the influence of environmental variables (total suspended matter, temperature, conductivity, nutrient concentrations, hydrology, phytopla...

wetlands are often considered sinks for contaminants, and aquatic plants have been shown to play important roles in wetland biogeochemistry through their active and passive circulation of elements. in this research, in order to evaluate the concentration level of heavy metals released by the urban, industrial and agricultural activities at the margin of the rivers flowing into anzali lagoon, as...

Understanding the biotic and abiotic factors that influence the susceptibility of a community to invasion is beneficial for the prediction and management of invasive species and the conservation of native biodiversity. However, the relationships between factors and invasibility of a community have not been fully confirmed, and the factors most associated with the susceptibility of a community t...

Aquatic organisms produce compounds that deter consumers, alter prey behavior, suppress or kill target and nontarget species, and dramatically affect food-web structure, community composition, and the rates and pathways of biogeochemical cycles. Toxins from marine and freshwater phytoplankton create health hazards for both aquatic and terrestrial species and can significantly affect human activ...

The order Saprolegniales includes pathogenic species of aquatic and terrestrial plants and aquatic animals including fish. These straminipilous fungi play an important role as a decomposing component which participates in the destruction processes of organic substrates and self-cleaning biological processes in freshwater ecosystems. In this study, samples of brown decayed twigs, leaves, woods a...