Effects of snail grazing and nutrient release on growth of the macrophytes Ceratophyllum demersum and Elodea canadensis and the filamentous green alga Cladophora sp.

摘要: The effects of snail (Lymnaea (Galba) turricula) nutrient release and grazing on young macrophytes filamentous green algae were examined in a laboratory experiment. Snails released an average 24.2 μg PO4-P 48.9 NH4-N g−1 FW d−1. consumed Cladophora sp. at the highest rate (45 mg d−1), Elodea canadensis lower (7 Ceratophyllum demersum lowest (2 d−1). Snail nitrogen phosphorus rates increased with temperature affected by food that was consumed. After 10 days exposure mesocosm experiment, snails reduced biomass E. canadensis, but had no effect C. demersum, which resulted becoming dominant species. Grazing environment-conditioning stimulated growth null or negative canadensis. Selective associated regeneration can affect taxonomic composition macro autotrophs lake littoral zones.