Logging is underway in areas of East Kowen and some mountain bike trails are closed.

The warning comes after reports of "several instances where people have ignored the closure signs", an environment, planning and sustainable development directorate spokeswoman said.

"These individuals endangered themselves by entering closed areas where trees are being felled," the spokeswoman said.

Volunteer trail builders alliance Kowalski Brothers lampooned the law breakers on their Facebook page in a post titled closed means closed.

"Most people read the signs, do the right thing and find somewhere elsewhere to ride – then you get a few contenders for a Darwin Award," the post said.

"You know, the type of person who naturally assumes the rules do not apply to them then proceeds to look down the wrong end of a gun, bathe while using electrical appliances, use their hand to clear a blockage in an insinkerator or go riding in areas where clear fall operations are under way.

"Obey the signs in East Kowen and stay out of areas where forestry operations are underway. 'Nice guy, but he was pretty stupid…' is not something you want on your headstone."

The clear felling operations are set to knock out part of the mountain bike trail network, however the government, in consultation with the Kowalski Brothers Trailworks alliance, has developed a plan to reduce the impact on mountain bikers.

The directorate spokesperson said the government was actively investigating ways of minimising the impact of forest harvesting operations on existing mountain bike trails.

The plan includes deferring harvesting of an allotment in East Kowen for a further five years. Additionally, staff from parks and conservation services are looking for other places within the forest that can be opened up for mountain biking.

"In discussion with mountain bike representatives, parks and conservation services is considering how changes to the order of harvesting operations over the next five years can help maintain a good visitor experience for bike riders at Kowen and still deliver on the government's commercial wood supply commitments," the spokeswoman said.

The government has also committed to enacting a sympathetic harvesting plan, meaning biking trails are identified on harvest plan maps and where possible, machinery avoid driving over and otherwise disturbing those tracks.

In addition, following the harvesting of the forest the parks and conservation service will test several techniques, "in addition to its normal site preparation methods", to help volunteers rebuild trails more quickly.

Greens MLA Shane Rattenbury wrote a letter to the government in June citing the importance of the trails at Kowen Forest for both local riders and as a tourist destination. He implored the government to consider halting the forestry work until an "assessment of the trails as assets is considered in the Cycle Tourism Strategy".

The Cycling Tourism Strategy is expected to be complete by October.