水分梯度对三江平原典型湿地植物小叶章地上生物量的影响

通过野外调查,研究不同水分梯度下三江平原典型湿地植物小叶章个体地上生物量季节动态、干鲜比(DW/FW)及生物量在构件中的分配特征.结果表明,小叶章个体地上生物量在小叶章群落中最大;各水分带小叶章地上生物量的时间动态呈双峰型变化特征,峰值出现时间随积水深度的增加而提前.生长季内,DW/FW随水分的增加而具有波动性,小叶章群落变化最大;灌丛一小叶章群落总体较低;常年积水的3个群落,不同生长期波动变化.小叶章地上生物量分配比:茎>叶>鞘;茎生物量比重,无常年积水群落大于常年积水群落;叶和鞘的生物量比重与茎相反.而水分梯度的直接作用以及各水分梯度下土壤环境条件是不同水分梯度带小叶章生长分异的主要原因.

Influences of water gradients on the aboveground biomass of a typical wetland plant (Calamagrostis angustifolia) in the Sanjiang Plain

Seasonal dynamics of aboveground biomass DW/FW and of biomass allocation in modules of Calamagrostis angustifolia,a typical wetland plant in the Sanjiang Plain,were studied in a field investigation.The individual aboveground biomass had the maximum value in a pure C.angustifolia community.Aboveground biomass under various water gradients all showed a double-peaked variation through the growing season,with the maximum value coming earlier with more water.During the growing season,biomass DW/FW took on a wave-like change as the water level increased.The ratio changed most in a pure C.angustifolia community and least in a spiraea salicifolia-C.angustifolia community,and had different values at different growth stages in the three communities with surface water present all year.The biomass allocation pattern was stems>leaves>vagina.The proportion of stem biomass was highest in the communities with no surface water,while proportions of leaves and vagina were highest in communities with surface water.The direct effects of water gradients on soil characters are the main reasons for growth variations of C.angustifolia.