Investigation of zooplankton community and size structure in different nutrient and water level among latitudinal gradient a mesocosm experiment

Higher temperature could have severe impact on ecosystem function as consequences of community changes. Thus lakes are very sensitive to warming. We assessed the effects of nutrient and water level changes on zooplankton community composition and size structure in different climate zones by running a standardised controlled six-month experiment in six countries. The mesocosms were established with two different nutrient levels and two depths, all run with four replicates. We analysed pooled zooplankton samples originating from monthly samplings of each mesocosm throughout the study period. We found a significant effect of temperature on the community composition and size structure of the zooplankton. However, no water depth and nutrient effect appeared. In all countries except for Greece, zooplankton community biomass was mostly dominated by cladocerans. The normalised size spectrum (NSS) slope increased with temperature but did not differ among depths or nutrient levels. The slope of NSS was shallower in Greece than in the other countries. Neither taxonomic diversity nor size diversity showed clear pattern at different nutrient or depth level along temperature gradient. However, genus richness decreased through warmer regions. Our experiment generall