The primary roles of green landscaping trees and shrubs encompass enhancing environmental quality, beautifying urban landscapes, and promoting ecological balance in multiple aspects.

Firstly, landscaping trees play a crucial role in improving environmental quality. They absorb carbon dioxide and release oxygen, thereby purifying the air. Moreover, these trees can regulate air humidity, absorb harmful gases and dust, and reduce pollution. Certain tree species, such as Robinia pseudoacacia, Sophora japonica, and Ligustrum, exhibit strong resistance to toxic gases like sulfur dioxide and hydrogen fluoride, and can tolerate high levels of dust and smoke pollution. These characteristics make landscaping trees highly effective in air purification and pollution reduction.

Next, ornamental greenery plays a significant role in enhancing the urban landscape. It increases green space, beautifies the environment, and improves the visual appeal and quality of life in cities. The aesthetic value of trees extends beyond their form and color, as they also impact psychology and emotions. Ornamental greenery can alleviate tension and fatigue, contributing to physical and mental relaxation.

Greening trees play a significant role in promoting ecological balance. They can stabilize soil, prevent soil erosion, and act as a barrier against wind and sand. Additionally, these trees help reduce noise pollution and serve as a firebreak, thereby maintaining the stability and safety of ecosystems.

In summary, greenery and seedlings have made significant contributions to enhancing urban environments and the quality of residents' lives by improving air quality, beautifying city landscapes, and promoting ecological balance in multiple ways.