Urban Diversity Impact on Plant Species Due to Environmental Conditions

摘要

Urban parks and road greening are important components of primary gardens, and their plant communities are based on the ecology of different management and operation modes. Urban greening is the link connecting the city segment isolation green space, good road greening can not only achieve the effect of greening, beautification, but also play a role in purifying the air, reducing noise, reducing radiation heat, and protecting the road surface, to people's travel and life to create a safe, pleasant, comfortable, beautiful, and hygienic environment. In this paper, through the Karachi main road and parks greening geo-spatial survey found that it contains 32 tree species, of which 4 species of naked plants, quilt plants 28 species. Road green tree species have a low diameter level and are in their infancy. The tree species of road greening in each district are mainly trees, and the important value of trees is much higher than that of shrubs. The diversity index of green tree species in each district is low, and a few tree species in each district account for more than 50 of all trees. By measuring the light intensity, air temperature, relative humidity and wind speed of different road greening forms, the effects of different road greening forms on small climate, environmental comfort and air flow are analyzed, and the results show that the greening forms of roads with large vertical projection area on the road are the most obvious in reducing light intensity, reducing air temperature, and increasing relative humidity. Trees in the road vertical projection area of large road greening form so that the road environment is in a comfortable situation throughout the day, conducive to human health. Trees in the road above the vertical projection area of the road green form can better reduce the road near the surface temperature, but trees in the road vertical projection area of small road greening.