公路边坡植物群落多样性与土壤因子耦合关系

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

为促使高速公路边坡植被群落正向演替,探究植物群落多样性与环境因子的响应关系,以山东省青临高速公路16种典型绿化护坡类型为例,选取代表植物群落、地形条件和土壤特性的指标,运用冗余分析法揭示植被重建后群落多样性与环境因子的关系,并运用灰色关联度构建不同护坡模式下植被-土壤耦合模型。结果表明:1)各类环境因子共同解释了公路边坡植物多样性变异信息的87.599%,土壤理化性质的解释度最高,达到69.539%;2)多样性指数对土壤作用的反馈程度排序为Margalef指数>Shannon-Wiener指数>Simpson指数>Pielou指数;3)与群落多样性平均关联系数大于0.65的土壤因子排序为速效磷>全磷>全氮>全钾>有机碳,属于较强关联;4)公路边坡植被-土壤的耦合协调程度以弱协调和中等协调为主,耦合度排序为土质边坡>岩质边坡>岩土混合边坡。该研究可为山东省乃至华北地区公路边坡植被恢复提供参考依据。

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 explained69. 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.