British artist Daniel Lismore stands alongside work by US artist Grace Weaver, which is featured in an exhibition at the Koppe Astner gallery, at the Frieze art fair in London on Wednesday. [Adrian Dennis/AFP]

Chinese artists have a strong presence at London's preeminent four-day contemporary art fair, Frieze, which opened on Thursday.

A 9-meter-long tree branch installation by Zeng Fanzhi, a top-selling Chinese artist, takes center stage in Frieze's sculpture park.

Other works turning heads include Ouyang Chun's paintings and an installation reflecting the complexity of the human psyche, as well as Chen Wei's photographs about dance halls and their influence on youth culture.

The participation of Chinese galleries comes at a time when global collectors are increasingly buying Chinese art, due to their increasing understanding of China and Chinese art's unprecedented international exposure.

Overseas sales of Chinese art more than quadrupled between 2009 and 2015, totaling $2.6 billion, according to a report by New York-based art market website Artnet and the China Association of Auctioneers.

Last year, Chinese art accounted for almost one-third of global art auction values.

Jonathan Stone, chairman and international head of Asian art at auction house Christie's, said Chinese contemporary art is a "worldwide phenomenon".

"It has gone beyond the stage of emerging, and to say it is 'an emerging trend' is actually diminishing it. It is significant and will stay that way," Stone said.

Most buyers of Chinese art in international markets are private collectors who have a genuine appreciation of Chinese art, Stone said, adding that Chinese contemporary art is characterized by its "ability to communicate a wide range of messages, including China's social and cultural development, and artists' emotions".

Colin Sheaf, head of Asian art at London auction house Bonhams, said Chinese art makes up a growing portion of its sales. He said Chinese nationals living in China and overseas are major bidders.

In addition to its role at the Frieze art fair, Chinese work is a major part of other events, including Art16 and the London Art Fair.

Fay Yeong, artist program manager at ShanghART gallery in Shanghai, said participation at art fairs is important for both sales and the building of the international reputations of artists, because they give artists the chance to be spotted by gallery owners and museum curators.

ShanghART, which represents about 40 Chinese artists, is showing at Frieze for the third year.

Meanwhile, the government-backed Chinese Visual Art International Promotion Program is staging an exhibition called Root Scene at the China Exchange in London this week, to coincide with Frieze.

Root Scene features 50 Chinese contemporary art works that combine modern realities with traditional Chinese culture.

"Chinese cultural roots are important for contemporary Chinese artists and make us unique," said He Jinwei, an artist who is showing paintings of Chinese "left-behind children".

Guo Jin, who is displaying sculptures of wreckage to symbolize the remains of failure after an attempt to succeed, added that Western attitudes toward Chinese art have changed significantly since the 2008 financial crisis. He said the change has gone from curiosity to communication as equals, supported by Chinese artists' newfound confidence.

Chinese art is now valued as highly as art produced by leading Western contemporary artists, Guo said.