Species Diversity of Spontaneous Herbaceous Plants in the Green Belt Areas of Beijing
The species diversity of urban spontaneous herbaceous plants directly affects the stability of urban ecosystem.Understanding the species diversity and influencing factors of spontaneous herbaceous plants in the Green Belt Areas is crucial for urban greening and regional biodiversity conservation.This study investigated the plant diversity in the Green Belt Areas of Beijing through transect and quadrat surveys conducted from July to September in 2022 and 2023.The species composition of urban spontaneous herbaceous plants was recorded,and the biodiversity characteristics of the understory herbaceous layer under 8 major tree species and 4 major shrub species were compared.The effects of stand structure on species diversity were analyzed using correlation and stepwise regression analyses.The results showed that:(1)A total of 334 species,220 genera,and 70 families of spontaneous herbaceous plants were recorded.Asteraceae had the largest number of species(84 species).The frequencies of Taraxacum minutilobum,Viola prioantha and Setaria viridis were higher,with the frequencies of 48.82%,48.03%and 46.46%,respectively.The most abundant species were Orychophragmus violaceus,Viola prioantha and Setaria viridis with abundances exceeding than 1 000 individuals.(2)The species diversity of understory spontaneous herbaceous plants was higher under Populus tomentosa and Platycladus orientalis,with diversity indices greater than 0.80,while it was lower under Sophora japonica and Pinus tabulaeformis,with indices less than 0.50.Among shrub species,Syringa oblata showed higher diversity(indices greater than 0.7),while Prunus davidiana had lower diversity(indices less than 0.50).Significant differences were found in the Shannon-Wiener diversity index and Simpson dominance index between different tree species,and in the Simpson dominance index among different shrub species.(3)Canopy density,stand density and mean DBH were negatively correlated with species richness and the Shannon-Wiener diversity index of understory spontaneous herbaceous plants.Canopy density had the strongest correlation,with correlation coefficient of-0.559 and-0.424,respectively.Species diversity was higher in tree-grass composite structure than in three-dimensional structures.Biodiversity indices decreased as shrub layer coverage increased in three-dimensional structure.The results indicate that the species richness of spontaneous herbaceous plants in the Green Belt Areas of Beijing is relatively high,with notable differences in biodiversity among tree species.The diversity of urban spontaneous herbaceous plants is primarily influenced by the light transmittance of the forest canopy in different stand structures.
spontaneous herbaceous plantsspecies diversitystand structurethe Green Belt AreasBeijing
万方数据
维普
