Modeling the degree of coupling and interaction between plant community diversity and soil properties on highway slope

In order to accelerate positive succession of the vegetation on highway slope and explore the response relationship between plant community diversity and environmental variables,we studied 16 typical slope protection patterns applied to Qing-Lin Highway in Shandong Province,eastern China.Seventeen variables representing diversity characteristics,topographic features and soil properties were selected for analysis,correlations between community diversity and environmental variables were examined by redundancy analysis,and the degree of coupling and interaction between vegetation and soil was modelled.Our results indicated that:1) all environmental variables in the study jointly predicted 87.599% of the variance of community diversity on the highway slope,and soil properties had the greatest effects which explained 69.539% of the variance. 2) Based on the degree of response of diversity patterns to soil factors,the order of diversity indexes from strong to weak was Margalef index,Shannon-Wiener index,Simpson index,and Pielou index. 3) The major soil factors closely associated with plant community diversity were ranked as available phosphorus,total phosphorus,total nitrogen,total potassium,organic carbon,and all of their average correlation coefficient was greater than 0.65. 4) The coupling coordination between vegetation and soil on the highway slope was mainly in weak and medium level.According to the degree of coupling,the sequence of three slope types was soil slope,rocky slope and geotechnical slope.The research may provide some references for vegetation restoration on the highway slope in Shandong Province and even North China.