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Phytoplankton Ecology (phytoplankton + ecology)
Selected AbstractsEffects of Nutrients, Fish, Charophytes and Algal Sediment Recruitment on the Phytoplankton Ecology of a Shallow LakeINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 6 2007María-José Villena Abstract The influence of nutrient levels, fish density and charophytes on the phytoplankton ecology of a shallow Mediterranean lake was studied by means of an in situ mesocosm experiment. Different levels of nutrients and fish were added over the course of an eight-week experiment, during which charophytes were removed towards the end. After submerged plants were removed, phytoplankton biomass increased significantly in all the mesocosms, with a reduction of algal diversity and species richness and dominance of cyanobacteria. Cyanobacteria recruited from the sediment played an important role in sustaining planktonic populations of the dominant species. Oscillatorial species (Pseudanabaena galeata, Planktolyngbya limnetica) dominated at higher nutrient levels (0.5,1 mg L,1 P and 5,10 mg L,1 N) and chroococcal cyanobacteria (Merismopedia tenuissima) at lower nutrient levels. Density of planktivorous fish had little effect on the algal recruitment from the sediment and phytoplankton biomass and diversity. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The concepts of ,plant functional types' and ,functional diversity' in lake phytoplankton , a new understanding of phytoplankton ecology?FRESHWATER BIOLOGY, Issue 9 2003Guntram Weithoff Summary 1. This is a discussion of the applicability to the phytoplankton of the concepts of ,plant functional types' (PFTs) and ,functional diversity' (FD), which originated in terrestrial plant ecology. 2. Functional traits driving the performance of phytoplankton species reflect important processes such as growth, sedimentation, grazing losses and nutrient acquisition. 3. This paper presents an objective, mathematical way of assigning PFTs and measuring FD. Ecologists can use this new approach to investigate general hypotheses [e.g. the intermediate disturbance hypothesis (IDH), the insurance hypothesis and synchronicity phenomena] as, for example, in its original formulation the IDH makes its predictions based on FD rather than species diversity. [source] Effects of Nutrients, Fish, Charophytes and Algal Sediment Recruitment on the Phytoplankton Ecology of a Shallow LakeINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 6 2007María-José Villena Abstract The influence of nutrient levels, fish density and charophytes on the phytoplankton ecology of a shallow Mediterranean lake was studied by means of an in situ mesocosm experiment. Different levels of nutrients and fish were added over the course of an eight-week experiment, during which charophytes were removed towards the end. After submerged plants were removed, phytoplankton biomass increased significantly in all the mesocosms, with a reduction of algal diversity and species richness and dominance of cyanobacteria. Cyanobacteria recruited from the sediment played an important role in sustaining planktonic populations of the dominant species. Oscillatorial species (Pseudanabaena galeata, Planktolyngbya limnetica) dominated at higher nutrient levels (0.5,1 mg L,1 P and 5,10 mg L,1 N) and chroococcal cyanobacteria (Merismopedia tenuissima) at lower nutrient levels. Density of planktivorous fish had little effect on the algal recruitment from the sediment and phytoplankton biomass and diversity. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 132 Parasites and Phytoplankton, with a Special Emphasis on Dinoflagellate InfectionsJOURNAL OF PHYCOLOGY, Issue 2003M. G. Park Eukaryotic parasites are believed to play important roles in phytoplankton ecology and particularly in bloom dynamics of red-tide dinoflagellates. Apart from the prokaryotic parasites such as viruses and bacteria, certain flagellates and fungi have received some degree of attention as eukaryotic parasites of phytoplankton. Our understanding of fungal parasites is largely based on studies for freshwater diatoms and dinoflagellates, although fungal infections are known for some marine phytoplankton, including diatoms. By comparison, the dinoflagellate genus Amoebophrya and the newly described Perkinsozoa Pavilucifera infectans are widely distributed in coastal waters of the world and are well known as eukaryotic parasites of dinoflagellates. Recent work indicates that these parasites have significant impacts on the ecophysiology and behavior of dinoflagellate hosts. Thus, the ecological roles of Amoebophrya spp. and Pavilucifera infectans should be carefully considered in developing concepts about plankton dynamics and material flows in marine food webs. [source] | ||||||||||