More than 100 experts specializing in ecology, botany, and environmental protection convened in early June in Lhasa, capital of the Tibet Autonomous Region, for the conclusion of an overall official check-up of the environmental protection projects enforced for the Qinghai-Tibet Railway, the world's highest extending for the longest distance through a permafrost area on the Roof of the World.

To make the appraisal, a one-year-long field investigation had been carried out by experts from the State Environmental Protection Administration, the Ministry of Railways and CAS, producing An Investigative Report on the Environmental Check-up in the Section of Railway Pavement between Golmud in Qinghai Province and Lhasa.

As part of the environment protecting initiative, scientists with the CAS Institute of Zoology were commissioned in 2003 to conduct environment research for the railways, such as the environmental impact on the surroundings, animal passages across the Railway, the wildlife-monitoring along the Railway during its construction, etc.

At the suggestions of the scientists, 33 passages have been built in the migratory routes of animals. They have played a positive role in helping promote the seasonal or annual migration or the genetic exchange within or between different populations along the Railway. In this way, the chiru, or Tibetan gazelle (Pantholops hodgsoni), for example, is gradually making themselves familiar with these channels on their migrating rut.

At present, the wildlife monitoring projects along the Railway commissioned to the CAS institute is still going on.