北川滑坡迹地植物群落多样性变化及环境解释

  目的  研究震后滑坡迹地生态恢复过程中群落植物多样性变化情况及环境解释。  方法  以北川县凤凰山滑坡迹地土壤和植物群落为对象，将滑坡迹地分为滑坡区、过渡区和未滑坡区，通过典范对应分析(CCA)排序法对3个区域植被变化情况进行分析，并对植物群落分布进行环境解释。  结果  ①2013—2019年，滑坡区和过渡区总体上植物科属种数量增加了4.00%~483.33%，未滑坡区减少了2.00%~37.50%。②滑坡区和过渡区的植物多样性增加了0.02%~483.33%，未滑坡区减少了2.00%~52.94%，且均匀度也有降低。③乔灌草层的CCA排序前2轴特征值之和占总特征值的60%~80%，表明前2轴包含了排序的大部分信息。④土壤pH和团聚体特征对植被分布的影响较大。  结论  滑坡迹地植物群落的多样性有所提高，且环境因子对植物群落有重要影响。图2表5参33

Changes of plant community diversity and environmental interpretation in Beichuan landslide site

  Objective  The objective is to study the variation of community plants diversity in the process of ecological rehabilitation of landslide slashed after earthquake and and make environmental interpretation.  Method  Taking the soil and plant communities in Mt. Fenghuang landslide slash in Beichuan County as the objects, the landslide slashes were divided into landslide area, transition area and non-landslide area. The vegetation changes in the three areas were analyzed by CCA (canonical correspondence analysis) method, and environmental interpretation was made with regard to the distribution of the plant community.  Result  (1) From 2013 to 2019, the number of plant families, genera and species in landslide area and transition area increased by 4.00%?483.00%, and that in non-landslide area decreased by 2.00%?37.50%. (2) The plant diversity in landslide area and transition area increased by 0.02%?483.33% while in non-landslide area decreased by 2.00%?52.94%, and the evenness also decreased. (3) The sum of the eigenvalues of the first two axes related to CCA ranking in arbor, shrub and grass layer accounted for 60%?80% of the total value, indicating that the first two axes contained most of the ranking imformation. (4) Soil pH and aggregate characteristics had a great impact on the vegetation distribution.  Conclusion  The diversity of plant communities in landslide slash has been improved to some extent, and the environmental factors have crucial influence on plant communities. Ch, 2 fig. 5 tab. 33 ref.]