Qinghai's Nangqian County is suffering desertification, declining water quality and falling wildlife numbers. Chakme Rinpoche, a local Buddhist lama, has started planting trees, along with monks and villagers. Winters 3,700 metres high are long and the trees struggle to survive, but the results are encouraging.

Chakme regularly takes trips into the mountains for environmental check-ups. On this journey, he found a fallen cypress tree. He tied his robes around its trunk and hauled it upright, saying it could still survive if pulled straight.

Non-biodegradable waste is very damaging to the grasslands, and if eaten by cattle or sheep can be fatal. When our group found some rubbish on the path, Chakme wrapped it up in his robe and slung it over his shoulder.

A flock of bharal, a protected species. The mountains are also home to the brown bear and snow leopard. Pastures have been broken up and fenced off, restricting wildlife to ever-smaller areas. Roads and cars increasingly encroach on their habitats. Chakme has organised a team of a dozen villagers to patrol the area.

At a tributary of the Lancang River, Chakme pointed out the gravel to the right of the photo. In the past, nobody dared harm the river, but increasing construction in Tibetan areas has led to rampant sand-mining.

Chakme visited the house of an elderly woman at her request. She hugged him, saying she did not have long to live. Her greatest hope, she said, was to be reincarnated as an animal that does not eat meat or harm other life. He later described her as a true Buddhist.

I accompanied Chakme to the annual Buddhist assembly, the most important event of the year for surrounding villages, when thousands come from near and far to read scripture. Tibetans sometimes save a sheep from slaughter in order to build up virtue. The animals are marked with coloured tags and will be left to live in peace.

This particular sheep was abandoned by its mother at birth. Its owner Yongzhuo took it home and breast-fed it alongside her own children. She believes the animal is the reincarnation of a dead relative. When the family set it free they named it after Chakme.

Chakme is building a museum, and the construction site has become the sheep's home. Chakme jokes that it keeps an eye on things when he’s not there.

After the assembly, Chakme organised a slingshot contest – an important skill for nomadic herders. By making it a form of entertainment, he said he hopes to preserve the tradition.

This elderly woman tried the slingshot many times. She wasn’t as good as the younger folk, but the villagers decided she deserved a prize anyway.

Chakme blesses the villagers to wish them a good caterpillar-fungus harvest. Caterpillar fungus, a valuable traditional medicine, is the most important source of income for the village. Chakme urged everyone to fill in the holes they dig, both to protect the grasslands and next year’s harvest.

Chakme on top of his museum, which will include an environment office and a school. “I don’t think Tibetan culture is the only good culture,” he told me. “Chinese and western cultures are equally precious. But as a Tibetan, I see my culture being lost, the environment worsening – I have a duty to protect my home.”