During her stay in her famous little wooden house research base in the 1980s, little wood thrushes would come to her and rest on her palms and dogs were her faithful companions. Even blood-sucking bugs seem to prefer her to others, Xu jokes.

"There was once about 400 leeches on me during one expedition. That's a record."

Known to her neighboring Tibetans as Siona Zhuoga, or "daughter of the forests", Xu has often been compared to Jane Goodall. And like Goodall, she has brought the spirit of her work with her wherever she has been.

When she retired in 1995 to Beijing, she brought back a little bit of Tibet where, as head of the Beijing's Lingshan Tibet Museum Park, Xu introduced Tibetan plant species to inland China.

"My priority right now is to spread a more-informed understanding of Tibet to the younger generations," Xu says. "Tibet's too precious. It can only live on well if everyone cares for it. It depends on the future generations."

To this purpose, Xu still lectures nationwide and gives guided tours to visitors to the museum park.

Dong Yongshu, Xu's assistant at the park for 15 years, says she is touched and transformed by Xu's endeavours.

"I used to be an ordinary clerk. But all of us are eco-conscious because of her. We recycle. We cut down on driving."

Xu has a maverick view of human beings versus nature.

"We are but one tiny element of the entire eco-system. We're like the ants. Why should nature comply to just our needs?"

Her book, Dream of Tibet, is "a heartfelt confession of my out-of-the-blue infatuation with Tibet" scheduled to come out next year. "Tibet is my cause. I'm a preacher for Tibet. A preacher for the way of nature."

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