震后边坡植被多样性与土壤特性的关系

The relationship between vegetation diversity and soil properties in earthquake slope

摘要:

通过对四川省北川县地震后生态恢复边坡的植物群落和土壤特性进行调查，并与周边未受地震破坏的自然边坡进行对比，记录了生态恢复边坡不同坡位样地的植物物种多样性和土壤特性因子，利用PCA排序和相关分析，研究了土壤特性与边坡植被物种多样性变化的相关关系。结果表明：与自然边坡相比，震后边坡坡下、坡中和坡上的物种多样性和土壤特性值都大幅度下降；震后边坡不同坡位的物种多样性和土壤特性差异较大，整体呈现出坡下>坡中>坡上的特点；相关分析表明，Margalef丰富度指数与碱解氮、速效钾和细菌数量呈极显著相关，Shannon-Wiener多样性指数与碱解氮、过氧化氢酶活性、细菌数量和放线菌数量呈显著相关；主成分分析结果显示，全钾含量、全磷含量、脲酶活性、蔗糖酶活性和真菌数量在北川土壤因子与物种多样性变化的协同作用中居于主导地位。

Abstract:

In this article, we carried out an investigation on the plant species and soil properties on eco-restored slope in Beichuan County of Sichuan Province, Southwest China, comparing with the natural slope which is not damaged by the earthquake. In our results, the plant species diversity and soil properties factors on different slope position were recorded, the principal component analysis and correlation analysis was adopted to study the connection of soil properties factors and the vegetation species diversity. We found that species diversity and soil properties earthquake slope were drastically reduced comparing to the non-damaged slope regardless of the slope positions. We also found that the variations of soil diversity and soil properties between different slope positions were much increased. In general, the difference of the bottom slope was larger than the middle slope, and the difference of the middle slope was larger than the top slope. Our data showed that the Margalef richness index had a close correlations with the local nitrogen, potassium and bacterial counts. Moreover, the Shannon-Wiener diversity index had much close relationships with the local nitrogen, catalase activity,bacteria and actinomycetes counts. Finally, ur principal component analysis showed that the total potassium contents, the total phosphorus contents, the urease activity, the sucrase activity and the fungi counts were the most important factors in the coaction of species diversity and soil properties.