BEIJING, March 11 -- Tree planting has helped China's greening efforts as volunteers planted 2.52 billion saplings across the country in 2013, a report showed on Tuesday.

According to the report released by the National Afforestation Committee Office, tree-planting had been promoted by the committee as well as the State Forestry Administration, aiming to protect forests, maintain ecological security and cope with climate change.

The report was released one day before a national tree-planting day on Wednesday, celebrated on March 12 each year.

Chinese forestry authorities also beefed up their efforts in ecological restoration and building last year, with the creation of forests totalling nearly 6.1 million hectares, according to the report.

The efforts were supported by extra funds, with the central government budgeting 145 billion yuan (23.6 billion U.S. dollars) for forestry in 2013, an increase of 9.9 billion yuan from 2012, the report said.

Meanwhile, the central government raised its subsidies to 9.13 billion yuan, for the promotion of better varieties of trees and forests last year, up 482 million yuan from 2012, the report said.

More efforts are needed though, the report said, adding activities still remain distant to arid regions, while problems such as low quality forests and grasslands, illegal logging as well as improper appropriations of forests, grassland and wet land pose challenges to the green drive.

Government data showed China's forest areas covered 21.63 percent of the country's land as of the end of 2013. The country aims to increase its forest coverage ratio to 23 percent by 2020.