At the same time, in cooperation with the local forestry department, they have vigorously cracked down on illegal activities, rescuing over 200 species of wildlife, such as the Oriental white stork, golden eagle, egret, swan, wild goose and roe deer.

As a biology teacher, Li believes that lessons cannot be confined to the classroom.

"There are over 180 plant species in our town, but the students rarely recognize the features and the benefits of different plants," he said. "I hope they can get close to nature, understand flora and fauna, and thus protect them."

In 2010, Li built a garden behind the school's office building, covering an area of over 300 square meters.

He planted various plants and noted their names and beneficial qualities, but due to a school expansion project, the garden had to be dismantled.

To create a field base for ecological conservation education, Li decided to build the botanical garden with his own savings.

"At first, I spent 600,000 yuan building the garden, which was originally intended to be used to buy a new apartment for my son," he said. "I received my wife's and son's support because they knew my favorite thing is to watch wild birds being released into the sky and returning to nature."

With an area of 260 hectares, the garden contains over 1,000 species of wild plants, nearly 600 varieties of Chinese medicinal herbs, over 70 species of wild birds and various terrestrial wildlife. It was open in April 2016 to the public for free.

Li has also continued to invest in road construction, housing and maintaining infrastructure at the garden. He has secured books on ecology worth 60,000 yuan through the China Wildlife Protection Association, and has built a reading room to accommodate them.

"Now the students can study and practice what they learn simultaneously in the garden," he said. "As a biology teacher and a national natural experience training instructor, I will always continue to teach about nature and cultivate a new force for the construction of an ecological civilization."

Contact the writers at zhouhuiying@chinadaily.com.cn