摘要：The importance of plastic responses to water depth as compared to non-plastic (developmental) changes in clonal morphology of the floating-leaved macrophyte Nymphoides peltata was examined in an outdoor pond experiment. All investigated clone characteristics, including clone weight and ramet number, had maximum values demonstrating optimal clonal growth at water depth of about 60 cm. Beyond the depth of 60 cm, these growth parameters were increasingly less than optimal. Biomass allocation to petioles of clones gradually increased with depth at the expense of allocation to roots. At the individual ramet level, most characteristics exhibited significant plastic responses to water depth. N. peltata seemed to be more plastic in the elongation of leaf petioles than in other organs in response to water depth. In addition, many ramet characteristics showed a significant non-plastic variation, with some characteristics changing with clone size irrespective of water depth. However, ramet weight and petiole length had no significant variation in shallow water, while they dramatically decreased among generations in deep water.
