高速公路边坡植被特征分析及护坡模式优化研究

Analysis of Vegetation Features on Slopes of Expressway and Study of Slope Protection Model Optimization

选取铜川至黄陵至延安高速公路(简称铜延高速公路)不同防护模式下的18个边坡为研究对象,分析了边坡植被特征。结果表明:(1)3种模式下,边坡的植被总盖度均大于60%,边坡的物种丰富度很低,物种数最多只有17种,Shannon-Weaner指数最高为0.85。(2)坡向和坡位对边坡植被的生长影响很大,植被盖度呈现阴坡>阳坡,下坡位>上坡位>中坡位。(3)现有的"苜蓿+柠条"和"小冠花+柠条"等植被组合呈现剧烈的种间竞争。(4)综合植被生长状况、物种丰富度及坡向坡位的影响,表现最好的是骨架植草模式,其次穴状整地植草模式,最差的是挂网喷播模式;物种组合"小冠花+柠条"最优,"苜蓿+柠条"其次,"苜蓿+黑麦草"最差。

This paper selected 18 slopes under the protection models of hole shape soil prepared seeding （HSSPS）, net-suspended spray seeding（NSSS）, framework seeding（FS） as study objects, analyzed slopes＇ vegetation features. The results indicate： （1）The slopes＇ plant coverage is higher than 60 % in three models. Plant richness is very low; The highest species number is 17. The highest Shannon-Wiener index is 0.85. （2） Slope gradient and position does a great effect on plants. Plant coverage Performances shady slopes sunny slopes, lower slopes 〉 upper slopes 〉 middle slopes. （3） In the vegetation combination way of ＂Medicago sativa L. ＋ Caragana korshinskii Kom.＂ and ＂Coronilla varia L. ＋ Caragana korshinskii Kom. ＂, there is intense inter-specific competition. （4） Consider the plants grow condition, richness and effects of slope gradient and position, the FS is the best model, and then is the HSSPS model, the NSSS model is worst. For the aspect of Species combination, ＂Coronilla varia L. ＋ Caragana korshinskii Kom. ＂ is the best way, then is the ＂Medicago sativa L. ＋ Caragana korshinskii Kom. ＂, the worst is the ＂Medicago sativa L. ＋ Lolium perenne L. ＂