Clonal Plasticity of Vallisneria spiralis in Response to Substrate Heterogeneity

Abstract

ABSTRACT Morphological plasticity of interconnected ramets grown in heterogeneous or homogeneous substrate patches was examined in the clonal submersed macrophyte Vallisneria spiralis. V. spiralis did not enhance biomass of clonal fragments by clonal integration in heterogeneous environments. However, more new ramets of clonal fragments were produced in heterogeneous patches. V. spiralis placed more ramets into nutrient-rich patches at the expense of performance of individual ramets. We conclude that clonal integration between interconnected ramets of this submersed macrophyte grown in heterogeneous substrate environments might be lost, but foraging behavior by placing ramets into favorable patches still occurred as in terrestrial clonal plants. The reason for loss of clonal integration in this submersed macrophyte grown in heterogeneous substrate patches may be that nutrient heterogeneity induced by substrate type was reduced by leaf nutrient uptake and translocation of nutrients between interconnected ramets was inhibited due to water saturation.