by Alessandra Cardone

ROME, March 21 (Xinhua) -- China's results in boosting urban green areas was one of the highlights of a special event held by the UN's Food and Agriculture Organization (FAO) here to mark the International Day of Forests, which is celebrated worldwide on March 21 since 2012.

Inspiring examples of green urban development were provided by the FAO in a special publication called "Forests and sustainable cities" launched to celebrate the date.

The report mentioned the best ways in which municipalities across the world used forests "to improve the living conditions of their citizens".

Along with other 14 cities -- including Bangkok, Phoenix, Ljubljana, Melbourne, Vancouver, and Lima -- Beijing was especially praised for its recent "reforestation program".

With its population of some 22 million, "one of the world's largest cities is being transformed by the establishment of large areas of urban and peri-urban forests," FAO said.

In the framework of a national plan launched by China in 2004, Beijing inaugurated "its largest afforestation program in its history".

Starting from 2012, over 54 million trees were planted on an area of 70,000 hectares in four years. Areas covered by forests would now represent 25.6 percent of the city plain, marking a 42-percent increase.

By the end of the program, the greater area of the Chinese capital could boast "23 forest patches with areas exceeding 667 hectares, and another 210 patches with areas greater than 67 hectares", the report highlighted.

"A unique feature of the afforestation is that these large new forests are on the periphery of urban areas," FAO experts also noted.

An urban forest ecosystem -- variously composed by large areas of woodlands, ecological corridors, green triangles, and multiple green belts -- was in fact "created between Beijing's central districts and its new city centers".

In its study, FAO also recalled China's overall effort to boost green urban development. Since after the State Forest Administration launched the "National Forest City" program in 2004, in fact, Chinese municipalities must meet 38 standards to acquire the status of national forest city.

"By 2015, more than 170 cities and 12 provinces were actively involved in the National Forest City program," FAO stressed.

Meanwhile, the land covered by trees in these urban communities rose to some 40 percent from less than 10 percent in 1981. "Nine cities on the Pearl River Delta in South China will become the country's first national forest city cluster, which should be completed by 2020," it added.

Since the UN established it in 2012, the International Day of Forest is celebrated on March 21 to raise global awareness on the importance of all types of forests.

This year, the event was devoted to cities and to the crucial role urban green areas can play in preventing or reducing pollution, soil degradation, and natural disasters such as floods and draughts.

"More than half of the world's population now lives in cities, and by 2050 almost 70 percent of the world will be urbanized," FAO said in a statement.

Yet, despite occupying less than three percent of the earth's surface, cities "consume 78 percent of energy, and emit 60 percent of carbon dioxide".