According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey f...According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.展开更多
This paper reviews various forestry practices in Jilin Province, China. The authors emphasize the rich natural diversity of Jilin and the need to focus research efforts on understanding the potential of native species...This paper reviews various forestry practices in Jilin Province, China. The authors emphasize the rich natural diversity of Jilin and the need to focus research efforts on understanding the potential of native species to meet the needs of land-management agencies involved in forest resource exploitation and ecological restoration. The native species of China hold great potential, and deserve more research attention, for meeting these needs. The introduction and testing of exotic species should be dbne only under rigorous scientific testing and after comparison with native species prior to operational introduction into forestry in order to avoid unwanted ecological consequences, including potential problems with alien invasives and pest introductions. The authors also emphasize the need to maintain viable （e.g., genetically diverse and reproductively fit） natural populations of native species in order to protect China＇s valuable natural diversity and maintain the potential of native species to function as future seed sources for local forest and ecological restoration activities.展开更多
基金the Natural Science Founda-tion of Guangdong Province (021740) and Guangdong Environmental Pro-tection Foundation (2001-18)
文摘According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.
文摘This paper reviews various forestry practices in Jilin Province, China. The authors emphasize the rich natural diversity of Jilin and the need to focus research efforts on understanding the potential of native species to meet the needs of land-management agencies involved in forest resource exploitation and ecological restoration. The native species of China hold great potential, and deserve more research attention, for meeting these needs. The introduction and testing of exotic species should be dbne only under rigorous scientific testing and after comparison with native species prior to operational introduction into forestry in order to avoid unwanted ecological consequences, including potential problems with alien invasives and pest introductions. The authors also emphasize the need to maintain viable （e.g., genetically diverse and reproductively fit） natural populations of native species in order to protect China＇s valuable natural diversity and maintain the potential of native species to function as future seed sources for local forest and ecological restoration activities.
