Abstract:

Weed invasion leads to the degradation of vegetation on the banks of roadways， affecting the recovery and stability of the ecosystem. Studying the species diversity and community characteristics of weeds on road banks is very important for understanding the pattern of weed community succession and for designing precise control methods. In this study， a contiguous grid quadrat method was used to investigate the vegetation on the road bank at seven sites along the Wenzhou Expressway in Zhejiang Province. We identified the species of weeds and the dominant species in the weed communities， and evaluated the diversity， stability， and similarity of weed communities. The results show that： 1） 65 species of weeds were present at the sampling sites， of which 47.69% were annual， 10.77% were annual or biennial， and 41.54% were perennial. Bidens alba， Geranium carolinianum， Youngia japonica， Erigeron sumatrensis， Miscanthus floridulus， Ipomoea triloba， and Lactuca indica were identified as the dominant weeds. 2） Patrick’s index and Shannon’s index were higher in B. alba-dominated communities than in other communities， whereas Simpson’s index and Pielou’s index were lower in B. alba-dominated communities than in other communities. Patrick’s index was lower in M. floridulus-dominated communities than in other communities， whereas Simpson’s index and Pielou’s index were higher. 3） The communities dominated by B. alba and M. floridulus were more stable than other communities. The similarity among different weed communities was low； i.e.， the types and numbers of species differed among the communities. Overall， our results show that the weeds on the banks of the Wenzhou Expressway mainly belong to the Asteraceae and Poaceae families. Because of their different growth habits， the invasion of B. alba （the representative weed of the Asteraceae family） has increased the diversity of communities， while the invasion of M. floridulus （the representative weed of the Poaceae family） has reduced the diversity of communities. These results indicate that different types of plants should be considered according to the local situation when replanting road banks to promote the formation of a stable and sustainable community system and enhance resistance to weed invasion.

Key words: slope, weed, species diversity, dominant species, community characteristics