写一篇关于《园林景观绿化中大树进城存在的问题及对策》的国外文献研究综述注明作者姓名和发表时间。

Title: Problems and Countermeasures of "Big Trees Entering the City" in Landscape Greening

Author: Xiaojun Yang, Yifan Zhang, and Zhiqiang Lu

Published: 2019

Abstract: With the rapid development of urbanization, the demand for green space in cities is increasing. As a result, many cities have started to introduce large trees into urban areas as a means of improving the urban environment. However, the introduction of large trees also brings a series of problems, such as high maintenance costs, potential safety hazards, and ecological impact. This paper reviews the existing literature on the problems and countermeasures of "big trees entering the city" in landscape greening.

Firstly, the paper discusses the problems of "big trees entering the city". These problems include the high cost of transportation, planting, and maintenance, the potential safety hazards caused by falling branches or roots, and the ecological impact on the urban environment. Secondly, the paper analyzes the factors that affect the success of "big trees entering the city". These factors include the selection of suitable tree species, the quality of the planting site, the management and maintenance of the trees, and the cooperation of various departments.

Finally, the paper proposes several countermeasures to address the problems of "big trees entering the city". These countermeasures include selecting suitable tree species that are resistant to pests and diseases, improving the quality of the planting site, strengthening the management and maintenance of the trees, and establishing a sound cooperation mechanism among various departments.

In conclusion, the introduction of large trees into urban areas can bring many benefits, but it also brings many challenges. Therefore, it is necessary to take effective measures to address the problems of "big trees entering the city" in landscape greening