US environmental groups have taken legal action against the Forest Service claiming it has used a federal law aimed at preventing wildfires to increase logging across 340,000 acres of Sierra Nevada national forests.

The Forest Service initially proposes to log 6,400 acres in the Plumas forest and wants to ramp this up to 340,000 acres throughout the region.

However, environmentalists claim the plan allows the felling of bigger and older trees and, through the lawsuit, hopes to force the Forest Service to conduct a full environmental impact review before it allows the cutting to go ahead.