Wulingyuan

Long ago, sand settled in a shallow sea and turned to rock.

Water wore the rock away along cracks, leaving tall pillars.

Scientists who measured how fast these pillars wear away (May and colleagues, 2018) explain that the rock is quartz-rich sandstone laid down in a shallow sea in the Devonian period, hundreds of millions of years ago. Later movements of the Earth's crust folded it and cracked it into a dense network of joints and fractures.

When the Himalayas began to rise, the land here was lifted too. Rivers cut down along the cracks and the rock walls between them slowly wore back, leaving pillars. The team's measurements suggest the peak forest started forming in the Pliocene, roughly 3 to 5 million years ago.

The pillars are cut from the Middle Devonian Yuntaiguan Formation, a fine-grained quartzitic sandstone about 520 m thick that built up in a shallow sea. Tectonic events between about 260 and 56 million years ago folded the rocks and left a dense network of joints and fractures. The onset of the Himalayan mountain building in the Neogene brought uplift, while a resistant cap of iron-rich quartz sandstone slowed erosion, leaving flat-topped mesas and steep valley heads often with waterfalls (May et al., 2018).

Using cosmogenic nuclides, May and colleagues found that valley floors at the base of the pillars wear down fastest (about 83 to 122 mm per thousand years) and peak-wall tops slowest (about 2.5 mm per thousand years). Their results suggest the peak forest began forming in the Pliocene, with estimates for most sub-catchments between about 3 and 5 million years ago, through river dissection along joints and faults followed by the retreat of the pillar walls.

Wulingyuan has stone bridges, caves and waterfalls.

One stone bridge is very high above the valley.

Between the pillars lie ravines and gorges with streams, pools and waterfalls. UNESCO counts more than 40 caves, with calcite deposits inside, and two natural stone bridges.

One of the natural bridges rises 357 meters above the valley floor. UNESCO adds that mists and clouds often wrap around the site.

Besides more than 3,000 columns and peaks, UNESCO lists natural bridges, ravines, waterfalls, streams, pools and caves under criterion (vii): more than 40 caves, notable for calcite deposits, and two natural stone bridges, one rising 357 m above the valley floor.

Dense broadleaf forest and the mists and clouds that frequently shroud the site add to the landscape's beauty (UNESCO).

Thick forests grow among the pillars.

Rare animals such as dholes and Asian black bears live here.

UNESCO says Wulingyuan has rich, lush plant cover and dense broadleaf forest, and is home to a number of endangered plants and animals.

Among the threatened animals UNESCO names are the dhole, a wild dog, the Asiatic black bear and the Chinese water deer. UNESCO also calls Wulingyuan an island of nature within a heavily populated farming region, and says it provides important habitat for these animals.

Luxuriant vegetation and dense broadleaf forest cover the site, which UNESCO says provides important habitat for a number of threatened plant and animal species, such as the dhole, Asiatic black bear and Chinese water deer.

At inscription, evaluators noted that with more information the site might also qualify under the biodiversity criterion (x).

Lots of people visit Wulingyuan every year.

Stay on the paths and keep the forest clean.

UNESCO notes intense pressure from visitors and tourist buildings, and says many measures have been taken to ease them, including promoting ecological tourism. Today UNESCO says the number of visitors, when they come and what they do are controlled and monitored.

PlayOwl's advice, built on UNESCO's notes: stay on the paths, keep a safe distance from cliff edges and take your litter home.

UNESCO lists human pressure from people living in and around the reserve, intense visitor pressure and the aesthetic impact of tourist facilities as integrity issues. From 1999 local authorities demolished houses in the scenic areas, expanded the scenic area, reduced settlement and promoted ecological tourism; by the end of 2002 the adverse impacts on the area's aesthetic values had been mitigated.

UNESCO says the number, seasonal spread and activities of visitors are now controlled, and their impact is monitored. PlayOwl suggests staying on paths, away from cliff edges, and leaving no litter.