Avoidance and tolerance to avian herbivores in aquatic plants

摘要: Tolerance and avoidance are the two contrasting strategies that plants may adopt to cope with herbivores. traits define degree which communities remain unaffected by herbivory. Trade-offs between herbivore competitive strength colonization ability shape population under In this thesis I present comparative experimental studies on populations of aquatic how they deal herbivory waterfowl. At level show compensation clonal pondweed \emph{Potamogeton pectinatus} strongly depends timing Herbivory aboveground biomass in summer reduces plant tuber production severely whereas predation tubers winter Bewick 's swans \emph{Cygnus columbianus bewickii} is largely compensated for. Despite high tolerance herbivory, fennel exhibit a flexible strategy towards burying deeper sediment presence swans. Since burial costly, trades for safety from support idea field an exclosure experiment. The extent species can adjust changes pressure constrained limits phenotypic plasticity microevolution. Therefore, at community level, trade-offs allow coexistence different thus stimulating functional diversity when heterogeneous space time. addition, influence interspecific competition itself possibly leading drastic within communities. This especially be case ecosystem engineers. charophytes (macroalgae) pondweeds shown mesocosm studies.