Mexico is cracking down on illegal logging in an effort to save millions of migrating Monarch butterflies.
The Monarch butterfly travels thousands of kilometres
Police and environmental inspectors have already closed down 17 sawmills to protect forests in Michoacan state, where the butterflies spend the winter.
They have also confiscated more than 300 truckloads of wood from illegally felled trees and arrested 28 people.
The Monarch butterflies migrate south from the US and Canada every autumn to escape the cold north American weather.
The sight attracts some 200,000 tourists every year who flock to the area in butterfly-watching season.
However, butterfly experts have warned that the long-standing problem of illegal tree-cutting in Mexico could end the Monarchs' annual journey if it is not stopped.
Details of the authorities' latest effort to curb the threat were disclosed at a news conference in Mexico City.
Mexico's top environmental prosecutor, Jose Luis Luege Tamargo, said illegal loggers faced jail sentences of three to five years.
However, prosecutors admitted that they were finding it difficult to combat the demand for illegally-harvested wood in the construction and furniture industries.
The authorities' initiative is backed by the "Grupo de los Cien", a group of Mexican intellectuals who are dedicated to protecting the environment.
The writer Homero Aridjis, who is president of the group, told the BBC that the government needed to take tougher measures.
He said: "They need to get to the bottom of it. They should go to the big sawmills and look for the politicians, the businessmen and the wood traders. They've never been touched."