Gu Yungui, who has turned a sharp slope into a forest more than 10,000 trees strong, nevertheless has bittersweet sentiments about his project. That's because the trees, which are largely rare and endangered, have yet to generate big profits, instead making Gu poorer than he was when he started the project.

The Yunnan man started planting rare trees in 2008. Gu spent his family's savings to plant the trees, and encouraged two of his sons to guard the forest after the trees grow big. In 2011, Gu moved closer to the growing forest to tend his seedlings. As the mountain gradually became green, the 10,000-plus seedlings thrived. Gu was confident that after two to three years, people would rush to buy his trees.

Once the trees were ready for sale, Zeng Qingwen, a botany research fellow, died after falling off one of the mature trees during a research tour. Zeng had previously encouraged Gu to plant more trees, and promised to buy all his trees when they grew big.

No one wanted to buy the trees after Zeng's death, and several small retailers who had been interested before stopped contacting Gu. Ultimately, Gu's income from the trees was around 70,000 RMB ($10,146), less than one-third of what he invested. Gu is still waiting for more buyers.

Ouyang Zhiqin, a senior engineer at the Environmental Science Research Institute of Yunnan province, who herself failed to keep alive the endangered manglietia hebecarpa tree, spoke highly of Gu's efforts. Ouyang said Gu did a better job than her research team. She has conducted five research projects in Gu's forest. She is now working to help expand Gu's business.

Gu is currently paid to find rare and endangered trees for Ouyang, who believes local people should protect biodiversity by establishing a mechanism for ecological compensation.