漓江水陆交错带不同立地类型草本植物根系特征

在漓江流域水陆交错带选取缓坡、陡坡、江心洲、人工岸坡4种典型立地类型,对主要优势草本植物的根长、根表面积、根系生物量、地上生物量、根冠比等指标进行了调查和比较研究。结果表明:(1)同一立地类型不同优势草本植物根系生物量、地上生物量、根冠比差异性均显著。各立地类型不同优势草本植物根长、根表面积均存在一定的差异性,其中不同优势草本植物根长度和表面积在陡坡和人工岸坡立地类型均存在显著性差异(p<0.05);根表面积在江心洲立地类型存在显著性差异(p<0.05)。(2)水蓼(Polygonum hydropiper)、小蓬草(Conyza canadensis)最适合生长的立地类型是缓坡类型;白背黄花稔(Sida rhombifolia L.)、土牛膝(Achyranthes bidentata Bl.)最适合生长的立地类型是陡坡类型;紫菀(Aster tatarian)、艾草(Artemisia argyi)最适合生长的立地类型是江心洲类型;葎草(Humulus scandens Merr.)最适合生长的立地类型是人工岸坡类型。

Root System Characteristics of Herbaceous Plants at Different Sites of Aquatic-terrestrial Ecotone of Lijiang River

The root system characteristics, such as root length, root surface area and root biomass in different soil depths were studied to assessed the correlation between root system characteristics and aboveground biomass, root-shoot ratio. This research was conducted on gentle slope, steep slope, middle bar and artificial bank slope of four typical site types on the aquatic-terrestrial ecotone of Lijiang watershed. The result showed that:(1) Within the same site type, the root biomass, aboveground biomass and root-shoot ratio of different main herbaceous plants were different significantly; Root length and root surface had some differences in different site type. On steep slope and artificial bank slope, there were significant differences between root length and surface area(p<0.05). On middle bar, the difference of root surface area was significant(p<0.05).(2) Polygonum hydropiper and Conyza canadensis grow best on the gentle slope. Steep slope was the most suitable site for Sida rhombifolia L. and Achyranthes bidentata Bl. The middle bar was the most appropriate area for Tatarian aster and Artemisia argyi. Artificial bank can provide the optimum environment for the growth of Humulus scandens Merr.