LHASA, June 5 (Xinhua) -- Southwest China's Tibet Autonomous Region spent more than 1.1 billion yuan (171 million U.S. dollars) on ecological conservation projects in 2017, the regional environmental bureau said Tuesday.

The projects range from grassland, wetland and wildlife protection to construction of nature reserves and afforestation.

In 2009, China introduced a 23-year plan with a total spending of 15.5 billion yuan to boost ecological conservation in the region.

Statistics showed that in 2017, Tibet had 47 nature reserves covering 412,200 square kilometers, or more than one third of the region's total territory.

Zhang Tianhua, deputy head of the regional environmental bureau, said the region has set up a special committee for monitoring the environment in Tibet and cracking down on illegal activities in the nature reserves.

Over the past five years, more than 60 regulations on ecological protection have been introduced in Tibet. Authorities investigated nearly 1,000 cases of environmental breaches.