LANZHOU, July 22 -- Sitting in the shade of a towering tree with her baby, Wang Muyun recalled the old days when she used to play games and pick locust flowers with kids under large trees.

"There are nine locust trees that are 500 years old around the block where I live," the 30-year-old woman said, adding that for generations, her family has shared the same memories of those ancient trees.

Wang's home is located in the city of Tianshui, northwest China's Gansu Province. Established some 2,700 years ago, the city is dotted with various old trees including locusts, elms and willows. Residents, from toddlers to the elderly, are able to enjoy the shack while chatting under the trees.

Thanks to continuous efforts made by the city since the mid-1980s, ancient trees in the city have been well protected.

According to the city's greening authorities, there are 267 ancient trees distributed in districts of Qinzhou and Maiji in Tianshui. Among them, 190 trees are more than 300 years old, and 77 are between 100 and 300 years old.

One of the oldest trees in Tianshui is about 2,500 years old, dating back to the Spring and Autumn Period (770-476 BC).

"Those ancient trees are living fossils and an important part of the old city's history and culture," said Liang Mei, director of the city's gardening management office.

"From an ecological perspective, ancient trees, especially rare trees and endangered plants, also play an irreplaceable role in maintaining the biodiversity, ecological balance, as well as environmental protection," Liang said.

In order to protect those ancient trees, Tianshui granted each ancient tree an "ID card" and had them all filed.

More efforts, including fertilization, disinsection, loosening the soil, and building guardrails, have been carried out to effectively protect those trees.

Tianshui is among hundreds of cities across the country participating in the campaign of ancient tree protection.

China rolled out a series of regulations nearly two decades ago, asking urban gardening and greening departments to undertake ancient tree research, so as to strengthen the protection and improve the management of ancient trees in cities.

Beijing has implemented a series of measures to strengthen the protection and management of over 40,000 ancient trees scattered in the city, including carrying out investigations, registration, classifications and filing, and increasing patrols of the city's trees, according to Beijing's greening authorities.

Last December, Beijing selected the 10 "most beautiful tree kings" in an effort to raise public awareness and enhance ancient tree protection.

The oldest tree in Beijing, a 3,500-year-old cypress, measuring 18 meters in height and with 18 branches, was among the crown winners.

In Shanghai, several major projects have been halted to protect the city's ancient trees. Residents are encouraged to "adopt" ancient trees to take care of them.

In the city of Nanjing, capital of east China's Jiangsu Province, GPS positioning devices have been introduced to enhance the management of ancient trees.