Effects of water depth on the growth of four emergent macrophytes
不同水深梯度对4种挺水植物生长繁殖的影响

The effects of water depth gradient (0 cm, 30 cm, 60 cm) on vegetative growth and ramets of four typical emergent macrophytes (Scirpus validus, Acorus calamus, Typha orientalis, Zizania caduciflora) were examined in this study. We found that: 1) deep water (60 cm) significantly reduced the growth and number of ramets in these four species; 2) the species represented to increase shoot height along the water depth gradient, and there was a trade-off between the above and under ground parts; 3) there are no differences in the number of ramets between shallow water (30 cm) and control (0 cm) groups in Z. caduciflora and T. orientalis, while the individual biomass and rhizome length varied greatly; 4) less ramets and shorter rhizomes were found in shallow water than control group in S. validus; 5) A. calamus represented the lowest morphological plasticity along water depth gradient. We suggested that Z. caduciflora and T. orientalis would be favored at 30 cm depth, S. validus at 0 cm depth and A. calamus at both 0cm and 30 cm depths.