A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the ...

Uses Background Concentrations Environmental Chemistry General Chemical Properties Mode of Action Fate in Soils and Water Lethal and Sublethal Effects General Terrestrial Plants and Invertebrates Aquatic Organisms Birds Mammals Recommendations Acknowledgments References Tables Number 1 Paraquat concentrations in field collections of selected organisms and nonbiological materials 2 Chemical and ...

The use of the monomolecular film Arosurf@ MSF as a mosquito larvicide was first reported by Ganett and White (1977). Since then, the efficacy of this larvicide on many mosquito species has been demonstrated in a wide variety of aquatic habitats (Levy et al. 1981, 1982; Mulla et al. 1983, Takahashi et al. 1984). Aquatic plants which occur in fresh and salt water habitats are an important source...

We describe the general background and the recent advances in research on underwater photosynthesis of leaf segments, whole communities, and plant dominated aquatic ecosystems and present contemporary methods tailor made to quantify photosynthesis and carbon fixation under water. The majority of studies of aquatic photosynthesis have been carried out with detached leaves or thalli and this sele...

To better understand their fate and toxicity in aquatic environments, we compared the aggregation and dissolution behavior of gum arabic (GA) and polyvinylpyrrolidone (PVP) coated Ag nanoparticles (NPs) in aquatic microcosms. There were four microcosm types: surface water; water and sediment; water and aquatic plants; or water, sediment, and aquatic plants. Dissolution and aggregation behavior ...

An experiment was conducted to investigate the response of periphyton biomass to addition of phosphorus (P) in an aquatic ecosystem dominated by submersed plants. Aquatic ecosystems dominated by Hydrilla verticillata (L.f.) Royle and Vallisneria natans (Lour.) Hara were constructed in mesocosm aquaria. Mesocosms were dosed weekly with different P loads (0 μg/L/Week and 100 μg/L/Week) for 17 wee...

Mercury at low concentrations represents a major hazard to microorganisms. Inorganic mercury has been reported to produce harmful effects at 5 microg/l in a culture medium. Organomercury compounds can exert the same effect at concentrations 10 times lower than this. The organic forms of mercury are generally more toxic to aquatic organisms and birds than the inorganic forms. Aquatic plants are ...

Hydrogen stable isotopes (δ2H) have recently been used to complement δ13C and δ15N in food web studies due to their potentially greater power to separate sources of organic matter in aquatic food webs. However, uncertainties remain regarding the use of δ2H, since little is known about the potential variation in the amount of exchangeable hydrogen (Hex) among common sample materials or the patte...

Aquatic plants have attracted attention in recent years because of the unexpected presence of CAM (e.g. Keeley 1981; Richardson et al. 1984) and C4 (Bowes & Salvucci 1984; Spencer, Wetzel & Teeri 1996; Reiskind et al. 1997; Keeley 1998a) photosynthetic pathways. Indeed, it now appears that the aquatic environment is home to as great a diversity of photosynthetic pathways as terrestrial environm...

The distribution of aquatic vegetation and associated community diversity and biomass in the Poyang Lake were investigated. The results showed that (1) 43 species of aquatic vascular plants were found in the Poyang Lake watershed which belonged to 22 families; (2) the vegetation of the Poyang Lake scattered in different areas which could be divided into 31 major plant communities and 5 plant zo...