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随着城市人口的增加,人类活动越来越强烈,对城市植被的影响也越来越大。根据广州城市植被的调查,由于强烈的人类影响,城市植被与自然植被有很大的不同。本研究是广州城市植被的土壤、物种多样性、行道树和生态功能的综合调查。研究结果表明:①广州城市街道和公园林地土壤的平均容重明显高于自然土壤的平均容重。行道树土壤的pH值偏高,而有机质和氮含量偏低。②城市植被的生物多样性偏低,城市公园森林群落乔木层只有1-16种。③在高密度城区树木的生长受到狭窄空间的限制,而人为的伤害则较为常见。④与生长较好的自然植被相比,城市植被的生产力偏低,从而影响到城市植被对碳氧平衡及污染物净化作用等环境功能。因此,应该改善城市植被的生长条件,增加城市植被的生物多样性,提高城市植被的生产力和生态功能,从而改善城市的生态环境。表5参18。
As the urban population increases, human activities become more and more intense, and the impact on urban vegetation is also growing. According to the survey of urban vegetation in Guangzhou, urban vegetation is very different from natural vegetation due to the strong human influence. This study is a comprehensive survey of soil, species diversity, street trees and ecological functions of urban vegetation in Guangzhou. The results show that: ①The average bulk density of soil in urban streets and parks in Guangzhou is obviously higher than that of natural soils. Road tree soil pH value is high, while the organic matter and nitrogen content is low. ② The biodiversity of urban vegetation is low, with only 1-16 tree layers in urban park forest communities. ③ The growth of trees in high-density urban areas is limited by the narrow space, while artificial damage is more common. ④ Compared with the natural vegetation with good growth, the productivity of urban vegetation is low, which affects the environmental functions such as the balance of carbon and oxygen and the purification of pollutants in urban vegetation. Therefore, we should improve the urban vegetation growth conditions, increase the biological diversity of urban vegetation and improve the productivity and ecological functions of urban vegetation so as to improve the urban ecological environment. Table 5 Reference 18.