(Reuters) - Six herders will stand trial on Wednesday in China's Inner Mongolia after trying to defend grazing land from expropriation by a forestry firm, in a case that will renew attention on rights abuses and the environment in the resource-rich region.

Ethnic Mongols have long complained that their traditional grazing lands have been ruined by mining and desertification, and that the government has tried to force them to settle in permanent houses.

Inner Mongolia, which covers more than a 10th of China's land mass and has the country's largest coal reserves, was rocked by protests in 2011 after an ethnic Mongol herder was killed by a truck after taking part in protests against pollution caused by a coal mine.

Ethnic Mongols make up less than 20 percent of the region's population of about 24 million.

The six ethnic Mongol herders are facing charges of "sabotaging production and management" and "intentionally destroying public or private properties", said Huhbulag, a lawyer appointed to represent the herders but later barred by authorities from doing so.

They were arrested in June after a clash with Chinese workers from the state-owned Wengniuteqi Shuanghe Forestry, two of the herders' family members told Reuters by telephone. The herders had accused the workers of illegally occupying their grazing land.

They could face up to seven years in jail.

"For years, the ordinary people have been disputing the land: they have petitioned and complained but there's been no solutions given," said Long Mei, the sister of one of the accused called Tulguur.

"The ordinary people survive on their land, now that it's been sold to other people, can the people be satisfied?"

Many Mongols in China go by only one name.

U.S. CONCERN

The trial comes three weeks ahead of a visit to China by U.S. Vice President Joe Biden, during which human rights will likely be raised amid a broader crackdown on dissent and freedom of speech and assembly.

The United States has expressed concern about the fate of China's most famous Mongol dissident, Hada, who was sent back to detention almost as soon as he completed a 15-year sentence for separatism in 2010.

Tulguur's wife, Sarangowaa, said he would not plead guilty. The herders' lawyer, surnamed Bai, declined to comment.

Officials at the court told Reuters they had no information on the case. Police said they had no knowledge about the case. Reuters was unable to locate contact information for the forestry company.

In April, angry herders dismantled a tent set up by the forestry company and demanded the immediate return of their grazing land, according to the New York-based Southern Mongolian Human Rights Information Center. A clash ensued, with 12 herders beaten and hospitalized, the group said.

"The authorities are determined to hand down long term jail sentences," Enghebatu Togochog, a member of the rights group, told Reuters.

Huhbulag said the herders were being made an example of.

"The case of these six herders is 'killing a chicken to scare a monkey', that is, if the people petition, they have the power to arrest you and put you on trial," he said.

(Additional reporting by Hui Li and Beijing Newsroom; Editing by Ben Blanchard and Robert Birsel)