5 Conclusion
In the present study, warming exerted mixed effects on the reproductive pattern of the four populations from different geographic sources. First, the variation in turion number output was complex among different populations and the turion biomass production maintained or increased under warming. Second, warming induced a metamorphosis shift in turions, as a lower percentage of oligophyllous turions and a higher percentage of pleophyllous turions generated. Lastly, a complete loss of sexual reproduction existed under warming. Generally, P. crispus showed an optimization in reproductive strategy through the adaptive phenotypic plasticity in reproductive pattern when facing warming scenario. The geographic distance likely induces local adaptation and the formation of different ecotypes of P. crispus . Since this mesocosm experiment used asexual propagules from warm temperate region of China, future studies should consider different propagule types and a larger scale of geographic sources for these propagules. Furthermore, a transplant experiment cross different climate zones may provide a global perspective in the reproductive strategy of clonal macrophytes and thus a deeper understanding in its evolutionary implications.