*2.1. Study Site*

The experiment was conducted in Xili University Town, Shenzhen (approximately 22◦3540"N, 113◦5820"E, 17 m above the sea). Shenzhen is a typical costal city in southern China and has a subtropical marine climate affected strongly by the south Asian tropical monsoon. Its mean annual temperature is 22.3 ◦C. January is the coldest month of the year, while July is the hottest. Its mean annual precipitation is 1924.7 mm, which mainly occurs from May to September. The mean annual sunshine duration is 2060 h, and the solar radiation is as high as 5225 MJ/m2.

Our study site located in an open square primarily covered by urban hedges (Figure 1). The two hedges consisted of an herb, *Hymenocallis littoralis* (0.4 m high), and a shrub, *Ligustrum quihoui* (0.5 m high); both of these greening species are common in Shenzhen. The area of the *H. lottoralis* hedge and the *L. quihoui* hedge were both about 40 m2. A *Zoysia matrella* lawn was located nearby and used for comparison with the hedges. The lawn's area was about 2000 m2.

**Figure 1.** Location of the study area. The upper left figure is the location of Shenzhen City. The upper right figure shows the location of the study area in Shenzhen. The bottom figure is a photo of the studied area by google earth. The studied hedges and lawn are in the red box.
