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

摘要：

公路路堑边坡不利的地形、土壤条件使得植被恢复和坡面安全受到挑战。客土喷播技术是一种应用于边坡防护的生态护坡技术。为了研究高速公路路堑边坡在进行客土喷播后,对应的长期生态恢复效果和水土保持效益,以广东省惠河高速公路客土喷播路堑边坡为研究对象,基于2003—2020年将近18年的路堑边坡植被调查数据,分析了客土喷播边坡的植被生长特征和物种组成变化,并利用水蚀预报模型对坡面植被的水土保持效果进行定量研究。结果表明：在客土喷播初期,植被能够快速覆盖坡面,3个月实现48%—61%的整体植被覆盖率,第2年后峰值盖度稳定在95%和88%左右,长期植被覆盖率保持在84%—96%左右,植被恢复速度和长期持续效果良好;植被物种组成在调查期间发生显著变化,在建植初期群落主要由初始喷播物种组成,此时优势种为狗牙根（Cynodon dactylon）等先锋植物,随着演替的进行,初始喷播物种逐渐被其他乡土植物取代,形成了以芒萁（Dicranopteris dichotoma）等草本植物为优势种的新群落,灌木植物对整体盖度的贡献逐渐提升,坡面物种丰富度逐渐增加,在第18年的调查中,在样方内共发现20种植物;客土喷播植被对于坡面土壤流失的控制效果显著,第1周年实现了68.6%和91.4%的土壤流失减少率,调查末期的年土壤流失减少率高于96%。因此,引入外来物种实现坡面植被快速恢复的做法是可行的,尽管这些物种存在时间可能较短,但在减少建植早期的坡面侵蚀和改善乡土植物定植条件上是有效的。该研究能为路堑边坡的生态防护设计和长期生态恢复效果预测提供重要的参考与借鉴。

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