关键词: 客土喷播, 植被恢复, 植物演替, 坡面侵蚀, 生态防护, 路堑边坡, 高速公路

Abstract:

The external-soil spray seeding (ESSS) is an ecological slope protection technology applied to slope protection, the unfavorable topography and soil conditions of the highway cutting slope makes vegetation restoration stability and slope safety challenged. To analysis the long-term vegetation restoration effects and water and soil conservation effects of the cutting slope of the highway restored by ESSS, the cutting slopes on the Huihe Highway in Guangdong Province, which were restored by ESSS, were taken as the research object, based on the long-term vegetation survey data from 2003 to 2020, the vegetation growth characteristics and species composition changes on the research slope were analyzed, and The water erosion prediction model was used to quantitatively analyze the erosion control effect of the slope vegetations. The results showed that in the initial stage after ESSS, vegetations covered the slopes quickly, achieved an overall vegetation coverage of 48% to 61% after 3 months, and the peak coverage stabilized at about 95% and 88% after the second year. The long-term vegetation coverage rate was maintained at about 84%-96%, which means the vegetation restoration speed and long-term continuous effect were good; the vegetation species composition has changed significantly during the investigation period. At the beginning, the vegetations were consist of the initial spraying species, the dominant species was Cynodon dactylon and other pioneer plants. With the succession of the community, the early sprayed species were gradually replaced by other native plants, forming a new community dominated with herbs such as Dicranopteris dichotoma. The coverage of shrubs and trees on the slope gradually increased, so was the species richness. In the 18th year of the survey, a total of 20 plants were found in the plot. the vegetations on the slope has a significant effect on the control of the slope soil loss. The annual soil loss reduction rates were 68.6% and 91.4% in the first anniversary, and the annual soil loss reduction rates were higher than 96% at the end of the survey. Therefore, it is feasible to introduce non-native species to achieve rapid restoration of slope vegetation. Although these species may exist for a short time, they are effective in improving slope erosion in the early stage of planting and native plant colonization conditions. This research can provide an important reference for the ecological protection design and the prediction of long-term ecological restoration effects for the cutting slopes

Key words: external-soil spray seeding, vegetation restoration, vegetation succession, slope erosion, ecological protection, Cutting slope, highway