The bishop said he hopes that President Arroyo, the Supreme Court and local government officials will listen to the peoples opposition to the project.
The groups marched from three points in the city and assembled at the plaza for the rally.
Those from northern Negros converged at the provincial capitol grounds, those from the south at the Lupit Church, and those from the east at the city high school.
Navarra said the recent flash floods and landslides in Sipalay, Hinoba-an and other southern towns that killed 14 people are examples of the ill-effects of forest denudation caused by lumber and mining firms.
"Never again will we allow another plunder of the only forest reserve we have on our island. Mt. Kanlaon is our life and we have to protect it," Navarra said.