From 2005 to 2010, Grumbine visited Yunnan for three to six weeks every year. He initially received private funding from a Canadian donor, and later funded his own trips.

In 2010, he joined the Kunming Institute of Botany as a senior researcher.

In his eyes, Yunnan, still less developed and with virgin forest, has great scientific value in biological research.

In his four years in Yunnan, Grumbine has hiked the mountains and spent most of his time in the countryside meeting local people, even though he couldn't speak the language. Gestures help, he says, although he now has the benefit of learning from his new wife, a Chinese researcher he met at a symposium in Xiamen, Fujian province.

One of his favorite spots is Shangri-la, where he has made about 20 trips since 2005. With the help of local guides, he hiked the Potatso National Park four times and studied the impact of the park on local livelihood and how effective local government was in managing the park.

"I usually camp or go to the village with a tent and some clothes. In the US, you are either in hotel or in tents, you have to carry everything, including food and shelter. But the difference here is that I can visit and stay with the villagers. They would share food, clothes with me," he says.

Not everything is rosy, according to Grumbine.

Lured by better income, villagers in Xishuangbanna were planting rubber and the plantations were changing the natural landscape. "Much of the rainforest is gone and replaced by plantations, and 20 to 25 percent of the entire prefecture is changed," he says. Local residents may have better income but there is a lack of sustainable planning. There is more money now, but there are also problems with water and ecosystems.

"The price of rubber in the global market fluctuates, so people may not have that much money in the future. That's what the local government should pay close attention to."

Grumbine has been trying to outline a bigger picture of how protected areas should work and examine whether Chinese environmental laws are strong enough to guide sustainable development that can meet international standards.

Grumbine says policy-makers have adopted an "economy first" creed since the opening-up and reform.

"I don't believe economic growth is the only purpose. Environmental protection, education and healthcare also matter. The old systems do not work any more, so this is a good time to change, with the new leaders pushing for better, greener policies."

Grumbine's tenure at the institute ends next year, but he is leaving with one promise: "This amazing land will bring me back."