银川市典型湖泊湿地中芦苇生长特性及其生境土壤因子研究

Study on Growth Characteristics of Reed and Its Habitat Soil Factors in Typical Lake-Wetland of Yinchuan

该研究以银川市典型湖泊湿地芦苇为对象,通过原位试验监测芦苇生长发育过程中生长指标的月份变化特征,建立形态指标与群落数量指标关系估测模型,分析影响芦苇生长的主要土壤因子,为湖泊湿地生态恢复工程和芦苇湿地的有效管理提供理论依据。结果表明:(1)银川湖泊湿地芦苇在5~7月间生长速率快(P<0.05),在8~9月份生长累积速率降缓(P>0.05),芦苇株高、盖度、生物量等指标峰值出现在8月或9月,10月份各生物学指标出现上下波动变化(P>0.05)。(2)银川湖泊湿地芦苇种群密度增加,群落环境改变,单株生存空间缩小,抑制了茎秆横向生长,表现为密度与茎粗呈极显著负相关关系;单株展叶数增加,单株叶面积伴随增长,群落尺度盖度和地上生物量也相应极显著增加(P<0.01)。(3)在5~10月,各月株高与地上生物量的关系可用幂函数模型或指数函数模型表达,生长初期表现出一定的正相关关系,之后随生长速率变缓这种正相关趋于减弱并消失;在6~8月,各月茎粗与单株地上生物量拟合效果依次增加,随单株地上生物量累积量越来越大,茎秆横向生长起到了物理支撑作用;形态指标与生物量指标在峰值期(8月或9月)拟合效果最佳,多为幂函数模型,表现为异速生长关系。(4)土壤全氮(TN)、土壤有机碳(SOC)、土壤碱解氮(AN)、全盐、pH、土壤速效钾(AK)均是影响芦苇生长的特征因子,并以TN、SOC对芦苇生长发育影响最大。

In this study,we selected the reed（Phragmites australis）of typical lake-wetland in Yinchuan to explore the monthly change characteristics of the growth index of reed,established the prediction model of the relationship between reed biological characteristics and analyzed the main soil factors affecting the growth of reed in habitat,which provides a theoretical basis for the ecological restoration of lake-wetland and the effective management of reed wetland.The main conclusions are as follows：（1）the growth rate of reed was fast in Yinchuan lake-wetland from May to July（P〈0.05）and the growth rate slowed down from August to September（P〉0.05）.The peak value of plant height,coverage and biomass appeared inAugust or September,and the biological indexes in October showed changes in the ups and downs（P〉0.05）.（2）In Yinchuan lake-wetland,the density of reed increased,the community environment changed,and the living space of individual plant was reduced,which inhibited the lateral growth of stem,and the density was negatively correlated with stem diameter（P〈0.01）.Leaf area per plant increased,leaf area per plant also significantly increased along with the increase of biomass and plant biomass in aboveground biomass（P〈0.01）.（3）The relationship between plant height and aboveground biomass can be expressed by the power function model or the exponential function model.The positive correlation between the plant height and the aboveground biomass in the early growth stage showed a positive correlation and then decreased with the growth rate.The aboveground biomass of June-August stem diameter increased with the increase of aboveground biomass,and the stem lateral growth has played a role of physical support.Morphological and biomass indices were best fitted in the peak period（August or September）,which were all power function models,which showed allometric relationship.（4）Soil total nitrogen（TN）,soil organic carbon（SOC）,soil available nitrogen（AN）,total salt,pH and available potassium（AK）were the characteristic factors affecting the growth of reed,and the effect of TN and SOC was the greatest on the growth of reed.