NANJING－In Yaoguan town of Changzhou city in East China's Jiangsu province, lichens have been recently spotted on mud and plant surfaces, which has not happened in around 30 years.

Although largely ignored, lichens, a collective of an alga and a fungus that live together and create a composite species, are sensitive to air pollution and serve as an early warning system for pollution in the environment.

"Lichen is looked upon as the environmental monitor because it is quite sensitive to automobile exhaust, industrial waste gas and acid rain," says Feng Hui, Party secretary of the town, adding that jellyfish and egrets have also appeared in the town in recent years, reflecting the improvement of the local environment and ecology.

Rare and endangered species have reappeared not only in the lakes, but also in the forests in Jiangsu and its nearby seas.

Butterflies are commonly recognized as valuable environmental indicators for their sensitive responses to subtle environmental changes.

Yang Guodong, a PhD from the Jiangsu provincial academy of environmental science, says they monitored 137 species of butterflies from 2017 to 2019 in Jiangsu, with the number on the rise from previous years.

"We found 165 rare and endangered species during the investigation. Most are more numerous and widespread than before," says Wang Beixin, a professor from the department of entomology in Nanjing Agricultural University.

As a region with plentiful natural resources and abundant species, Jiangsu attaches great importance to biodiversity conservation, according to the provincial ecology and environment department.

The province launched a plan to protect species biodiversity in 2014 and reinforced the protection of some endangered species in the Yangtze River in 2019.

The local government has set a "red line" for ecological protection in 407 regions and implemented strict space management. It also confirmed 22.49 percent of its land as ecological protection areas.

"The 31 nature reserves are sheltering 60 percent of species in the province," says Zhu Deming, an official with the provincial ecology and environment department, adding that Jiangsu is establishing a provincial-level data platform on biodiversity, open to the public to attract more people to engage in protecting various species.