【摘要】 为了研究芦苇在黄河三角洲潮水和淡水两种生境条件下的生长差异,特别是根系生态特征差异,分别在潮水区和淡水区选取长势均匀的芦苇群落,测量不同土层电导率、pH值,芦苇株高、密度、茎叶及不同土层主根、须根生物量、离子含量等指标。结果表明,两个区域的表层土壤（0—10 cm）电导率均大于下层土壤,并在20—30 cm土层处电导率测得最小值,而在更深的土壤呈现出随土层深度增加,电导率上升、pH值下降的趋势。潮水区芦苇的平均株密度和株高分别为（20.80±5.93）株·m^-2,（35.70±16.01） cm,淡水区芦苇的平均株密度和株高分别为（309.60±39.15）株·m^-2,（91.48±13.09） cm。在生物量分配上,潮水区芦苇的主根、须根、茎、叶生物量分配比例分别是79.70%、11.88%、6.79%和1.64%,而淡水区芦苇在这四个部位生物量分配比例分别是66.77%、8.76%、18.54%和5.92%。淡水区芦苇主根生物量主要集中在0—30 cm土层,须根生物量主要集中在0—10 cm土层（68.18±38.99） g·m^-2;潮水区芦苇主根生物量主要集中在20—30 cm土层（146.57±109.94） g·m^-2。离子含量结果表明,潮水区芦苇主根平均Na⁺和K⁺含量分别为（6.38±1.56） mg·g^-1和（1.08±0.17） mg·g^-1,并且Na⁺与Cl^-分布呈极显著正相关（P<0.01）。淡水区芦苇主根这两种离子平均含量分别为（2.82±0.56） mg·g^-1和（3.93±1.10） mg·g^-1。以上结果表明芦苇能够改变株高、密度、各部位生物量分配比例以及离子分布来适应不同水盐环境,这也是芦苇能够在高盐环境下长期生存的适应机制。更多还原

【Abstract】 In order to study the growth differences of Phrag,nites australis,especially the differences of root ecological characteristics,between the tidal and fresh water habitats of the Yellow River Delta,two typical habitats of P.australis in tidal and fresh water habitats were chosen,and the electrical conductivity（EC） and pH of different soil layers were measured;the height,density,biomass of stem,leaf,main and fibrous root and ion content in different soil layers of P.australis were also analyzed.The results showed that the EC of surface soil（0-10 cm） was higher than that of the lower soil in both habitats and the minimum EC was tested in 20-30 cm soil layer.However,with the increase of soil depth deeper than 20-30 cm,the EC value increased and the pH decreased.The mean density and height of P.australis were（20.80±5.93） stem·m^-2 and（35.70±16.01） cm in tidal area,（309.60±39.15） stem·m^-2 and（91.48±13.09）cm in fresh water habitat,separately.In terms of biomass allocation,the proportion of the main root,fibrous root,stem and leaf of P.australis in tidal and fresh water habitats were 79.70%,11.88%,6.79%,1.64% and 66.77%,8.76%,18.54%,5.92%,respectively.The main and fibrous root biomass of P. in fresh water habitat was mainly concentrated in 0-30 cm and 0-10 cm（68.18±38.99）g·m^-2 soil layer,respectively.And the main root biomass of P.australis in tidal water area was mainly concentrated in 20-3 0 cm（146.57±109.94） g·m^-2 soil layer.After analyzing the ion content of roots in two habitats,we found the average content of Na⁺ and K⁺in the main root of P.australis from tidal water habitat were（6.38±1.56） mg·g^-1 and（1.08±0.17） mg·g^-1 respectively,and the distribution of Na⁺ and Cl^-had a significantly positive correction（P<0.01）.The average contents of these two ions in the main root of P.australis in fresh water habitat were（2.82±0.56） mg·g^-1 and（3.93±1.10） mg·g^-1 respectively.The results show that P. can adjust the height,density and biomass allocation of different organs and the distribution of ions to adapt to the different salt-water environment,which is the typical adaptation mechanism of P.australis in high-salt areas.更多还原