广州市郊公路廊道旁适生植物

Suitable plants along the highway corridor in the suburb of Guangzhou

公路是人为修建用以促进人文交流与物质联通交换的廊道,对社会经济、文化的发展起着极为重要的基础支撑作用。由于公路廊道与林地生境条件相比差距较大,导致植物不易生长,如何通过生态恢复构建道旁植被,成为公路廊道生态建设的焦点问题之一。本研究选取广州郊区18条经历较长时间恢复的郊区道路设置了道旁样地,共144个样方,进行了植物群落调查和数据综合分析;比较了6条公路与邻近林内生境的环境因子;进一步测定了代表性优势适生物种的生理生态指标。试图解决如下科学问题:(1)道旁与林内相比,限制植物生长的环境要素有哪些?(2)在道路旁有哪些自然适生植物?(3)为什么这些植物能在道旁环境生长?主要结果如下:(1)广州郊区公路道旁生境较之林地,对植物的生长起了限制作用的生态因子是强光照、高温以及干旱。(2)筛选出33种道旁恶劣生境下自然生长的植物优势适生种,其中16种广泛分布在道旁和林地,17种广泛分布在道旁;常绿种有2种、落叶种有9种,落叶占比27.3%;乔木有24种、灌木有6种,藤本有3种,乔木占比约72.7%。(3)道旁自然生长植物具有阳性树种种数与数量增多,树木形态矮化,尖削度高,叶片总厚度、栅栏组织和海绵组织增厚等适应性变化特征,以及具有净光合速率、水分利用效率加快的生理生态特征;这些特征也很好地解释了其适应的机理,可作为道旁恢复物种筛选的科学依据。本研究揭示为什么这些植物能够在广州市郊区公路道旁生境下自然适生的机理,丰富了公路生态廊道生态建设理论;本研究所提出的适生优势种,可作为广州市郊区公路廊道植被快速生态恢复的优先物种选择,对其他区域的道路生态廊道建设也有参考价值。

Road is a corridor built by people to promote cultural and material exchanges,and plays an important role in the foundation of social,economic and cultural development.Because of the big difference in habitat between road corridor and forest interior,plants are not easy to grow.How to construct roadside vegetation through ecological restoration has become one of the focus issues of road corridor ecological construction.In this study,a total of 144 roadside plots were set up in 18 suburban roads in Guangzhou after a long period of recovery,in which plant communities were investigated,and then the data were comprehensively analyzed.We also compared the environmental factors of 6 rods with their adjacent forest interior habitats,and determined the physiological and ecological indexes of representative dominant suitable species.We try to answer 3 scientific questions:(1)What are the environmental factors restricting plant growth along the road compared with forest interior?(2)What are the natural plants in the roadside?(3)Why do these plants grow in roadside environment?The main results are as follows:(1)Compared with forest interior,the main ecological factors limiting the growth of plants in roadside habitats are intense light,high temperature and drought.(2)A total of 33 natural dominant species were selected,of which 16 were widely distributed along roads and in forest interior,and 17 were mainly widely distributed in the roadside.There were 2 evergreen species and 9 deciduous species;the deciduous species accounted for 27.3%.There were 24 tree species,6 shrub species and 3 vine species,accounting for 72.7%of the total.(3)The natural plants along the road had the characteristics of increasing number and quantity of positive tree species,dwarfing of tree form,high sharpness,thickening of total leaf thickness,palisade tissue and spongy tissue,etc.It has the physiological and ecological characteristics of higher net photosynthetic rate and water use efficiency;These characteristics also explain the mechanism of its adaptation,and can be used as the scientific basis for selecting species of roadside restoration.This study reveals the mechanism of why these plants can naturally adapt to the roadside habitat in suburban Guangzhou,and enriches the ecological construction theory of highway ecological corridor.The proposed biogenic dominant species is the priority species selection for rapid ecological restoration of highway corridor vegetation in suburban Guangzhou,and has a reference value for road ecological corridor construction in other areas.