Metacommunity Concepts Provide New Insights in Explaining Zooplankton Spatial Patterns within Large Floodplain Systems

Flood pulse related physical variables (FLOOD) can affect zooplankton community structure through local factors directly and can also influence through regional dispersal factors of metacommunity concepts indirectly. Therefore, we infer that spatial patterns of zooplankton communities could be related to metacommunity concepts and their importance may depend on the size of the aquatic/terrestrial transition zone (ATTZ). Herein, we explored the relative importance of limnological (LIMNO) and FLOOD variables in zooplankton community by analyzing data from 272 sites across three floodplain lakes in the middle reaches of the Yangtze River. Our results showed that the variation in the zooplankton community can be well explained by the LIMNO and FLOOD variables in all of the lakes under the low water level season. However, during the high water level season, neither LIMNO nor FLOOD can explain the spatial variances of zooplankton. Therefore, our results indicated that testing biogeographical theories and macroecological laws using zooplankton should consider temporal aspects of flood pulse. Furthermore, we noted that the number of explained variance by local variables is negatively correlated with the size of the ATTZ. Metacommunity concepts provide complementary insights in explaining zooplankton spatial patterns within large floodplain systems, which also provide a theoretical basis for ATTZ protection in floodplain management.

Zooplankton composition and abundance from Nideban Reservoir, Udgir Dist. Latur

Zooplanktons are the microscope free swimming organisms of aquatic system. There are represented by a wide array of taxonomic groups of which the members belonging to protozoa, Rotifera, Cladocera and Copepoda are most common and often dominate the entire communities. They have many remarkable features which hamper their predation by higher organisms. The members of Zooplankton community are important for their role in trophic dynamics, energy transfer in the aquatic ecosystem. They provide food for fishes in the water bodies and play a major role in the fish production. The zooplankton community was studied by monthly samples taken from Oct. 2018 to Feb. 2019. The reservoir water is used for agriculture and fishery activities.

Diversity of vascular plants and zooplankton communities in regard to the ecological assessment of the territory of the ecological park “Samara Venice”, Samara Region, Russia

The results of the floristic and hydrobiological studies performed in May - August 2020 on the territory of the ecological park Samara Venice (Samara Region, Russia) are presented. These data form the basis for the ecological assessment of the territory. The diversity of vascular plants is presented by 4 divisions, 65 families, 205 genera, and 309 species. Among them, 66 species (21.4%) belong to the alien plant species, including nine invasive. Habitats of the plants included in the regional Red List are found. The zooplankton diversity comprises 60 species and morphs. The zooplankton community has undergone significant transformation, manifesting by an increase in the total biomass and in the biomass of crustaceans and rotifers, and by a decrease in absolute and relative species richness. It is revealed that a number of the studied water bodies belong to the transitional type, and may be characterized as of middle position between the meso- to eutrophic type (moderately polluted and polluted waters).

Comparisons of Zooplankton Community Structure between with- and without- Pesticide Applications on Rice Fields

Herbicide usage in rice fields over time may have a direct and indirect influence on the biodiversity of the fields. The impacts of herbicide usage on non-target organisms were assessed by examining the species richness and zooplankton density of two rice fields. One was 2.08 hectares in size and had been treated with pesticides during the sampling year (RF-PA). The second field, measuring 1.76 hectares, had received no pesticide treatment (RF-NPA). Every two weeks, zooplankton was quantitatively collected from ten sampling sites in each field. At each station, 20 L of measured water was filtered through a plankton net with a mesh size of 20 µm and preserved in 1% Lugol’s solution. The results revealed that RF-NPA and RF-PA had 112 and 88 species of zooplankton, respectively, with an abundance-based Jaccard index (Jabd) of 0.438. The total zooplankton density in RF-NPA was 24.4 ind./L, significantly higher than the 16.6 ind./L in RF-PA (p < 0.001). The Shannon-Wiener diversity index (H’) and evenness (J) were highest in RF-NPA at the second sampling (3.45 and 0.75, respectively). These results indicate that glyphosate application affects the diversity of species and density of zooplankton in rice fields.

Seasonal Variation of Zooplankton Communities and the Effects of Environmental Factors in the Seawater Near Taishan Nuclear Power Station

In the seawater near Taishan Nuclear Power Station, Zooplankton community composition and abundance, the biomass of major taxa, vertical distribution pattern, together with several environmental factors were investigated to evaluate the variation tendency as the seasons change. The structure characteristics of the zooplankton community were analyzed by Margalef species richness (d), Shannon-wiener species diversity index (H’), Pielou evenness index(J’), zooplankton dominant (Y), and dominant species replacement rate (R). There are 48 species within 11 classes of zooplankton identified, including 32 species of copepods. Zooplankton species richness changed obviously in the four seasons, Spring saw the highest (8010.00 ind.m-3), followed by winter (5100.00 ind.m-3), autumn (1713.75 ind.m-3), and summer (1196.25 ind.m-3). Similar trends were observed for the wet biomass, which was highest in spring (215.90 mg.m-3), followed by winter (181.70 mg.m-3), summer (78.56 mg.m-3), and autumn (24.69 mg.m-3), which gave an annual average of 125.21 mg.m-3. The results indicate that the abundance and biomass in spring were significantly higher than those in other seasons. Altogether 8 dominant species were identified along the whole year: Acrocalanmus gibber, Bestiolina amoyensis, Paracalanus parvus, Acartia danae, Mesocyclops leuckarti, Noctiluca scientillans, Penilla avirostris, and Lucifer penicilliger. The annual average Shannon-Wiener diversity index, Margalef diversity index, Pielou evenness index were 1.75, 1.83, and 0.74, respectively. The effects of environmental factors on the zooplankton community were studied by R and canonical correspondence analysis (CCA). According to Pearson correlation analysis and canonical correspondence analysis, the most important environmental factors influencing the changes of zooplankton species composition, abundance and distribution were water temperature, salinity, and pH in the whole year.