Clonal growth and foraging behavior of a submerged macrophyte <i>Vallisneria natans</i> in response to water depth gradient

Abstract

为了解水深梯度对苦草克隆生长与觅食行为的影响,通过大型原位浮台实验,将苦草幼苗盆栽后悬挂在不同水深(1.0、2.5、4.0、5.5、7.0 m)下培养,比较其生物量、无性系分株数、出芽数、株高、最大根长和匍匐茎总长的变化,并且评估了植株生物量对这些性状的影响.研究结果表明,随水深的增加苦草的生物量、无性系分株数、出芽数、最大根长、匍匐茎总长均显著降低,而株高随水深梯度呈先增加后降低的趋势.植株生物量仅对出芽数没有显著影响.水深梯度与植株生物量的交互作用仅对无性系分株数和匍匐茎总长有显著影响,而对其他性状没有显著影响,说明这两个性状对水深的响应受到个体发育的影响.;To investigate clonal growth and foraging behavior of a submerged macrophyte Vallisneria natans, biomass, ramet number, bud number, total stolon length, shoot height and maximum root length responses of V. natans ramets were investigated experimentally at five water depths (1.0, 2.5, 4.0, 5.5 and 7.0 m). The study showed biomass, ramet number, bud number, total stolon length and maximum root length all decreased significantly with increasing water depths. The shoot height exhibited a unimodal pattern along with increasing water depths, with the maximum value at the water depth of 2.5 m. The plant biomass significantly affected all the growth traits except for the bud number. Furthermore, ramet number and total stolon length were significantly affected by the interactive effect between water depth and plant biomass, suggesting that the effects of water depth on ramet number and total stolon length were depended on plant development.