基于结构方程模型的昔榆高速公路边坡草本植物群落综合评价OA

Plant communities on highway slopes significantly affect the ecological environment.However,how the growth,community succession,and competition of different plant combinations affect the environmental productivity and stability remain unclear.Additionally,there are issues such as short-term effectiveness and poor sustainability of restoration and construction measures.Therefore,this study focused on slopes with different herbaceous plant configurations along the Xiyu Expressway.The specific configurations included multiple combinations,such as Medicago sativa+Elymus dahuricus+Astragalus laxmannii and Artemisia scoparia+Elymus dahuricus+Astragalus laxmannii.Three factors,soil physical properties,soil nutrients,and plant community characteristics,were selected as the criterion layer.A structural equation model(SEM)was used to establish an evaluation method for plant communities,and a comprehensive evaluation was conducted on herbaceous plant communities in 22 sample plots(each with an area of 6 m×10 m)along the expressway.The results showed that:1)For the SEM for herbaceous plant community evaluation,the χ2/df was 1.294,which fell within the range of 1～3.The CFI(comparative fit index),NFI(normed fit index),TLI(tucker and lewis index),and RMSEA(root mean square error of approximation)values were 0.974,0.921,0.963,and 0.032,respectively indicading that the model exhibits a good fit and meet the research requirements.2)The weights of plant communities,soil nutrients,and soil physical properties were 0.397,0.338,and 0.265,respectively.The criterion layer indicators that affected the comprehensive evaluation results were in the order of:Plant communities>soil nutrients>soil physical properties.This indicate that the assessment of plant community characteristics is the key to understanding the overall status of plant communities.3)The comprehensive evaluation scores of herbaceous plant communities in the 22 sample plots ranged from 1.53 to 4.58.Among these,three plots were rated as Grade Ⅰ,eight as Grade Ⅱ,seven as Grade Ⅲ,and four as Grade Ⅳ.These results suggest that the configuration of some herbaceous plant communities along the Xiyu Expressway requires optimization,and that the evaluation results objectively characterize the current status of herbaceous plant communities with different configurations along the Xiyu Expressway.This study showed that using SEM to evaluate herbaceous plant communities on this expressway yielded relatively reasonable results with certain reference value and provide a new analytical perspective and methodological reference for herbaceous plant community evaluation.