Loading The park is home to seven of Victoria's 1120 threatened plant species. Three of those are endangered, vulnerable or rare; the Small Scurf-Pea, Gilgai Blown Grass and Short Water Starwort. There are 290 species of indigenous plants in the park. The park contains some of the last remnants of original bushland in inner-Melbourne and is also home to numerous significant sites for the local Aboriginal community. Parks Victoria's area chief ranger Brendan Sullivan said that illegal trail construction has a "significant impact". "Some of the worst examples are trails built for downhill riding due to the vulnerability of the soil," Mr Sullivan said.

"The impacts aren’t just visual and short term, they are long-lasting and affect biodiversity and regeneration potential." Yarra River Keeper Andrew Kelly said he was alarmed by the erosion he sees. Andrew Kelly, Anna Ridgway and Lawrence Pope are concerned about the environmental damage mountain bike riding is doing at the Yarra Bend Park. Credit:Joe Armao "They're carving trails through the park and stripping off vegetation and creating erosion. The soil is pretty fragile and once surface soil is ripped off and it rains a channel forms, and soil falls onto the road," Mr Kelly said. "It's anarchistic. They cut wires on fences and they build jumps."

Mr Kelly said he had stopped to tell riders to be more careful and that he'd like to see riders on illegally built paths fined. "It makes the park look quite ugly when you hit these badly eroded parts. Runners and walkers do much less damage." While plants has been impacted by mountain bike riding over the past few decades, no culturally significant sites have been harmed, although Mr Sullivan said there is potential for this to happen if the practice continues. Parks Victoria wants mountain bike riding in the park restricted to one trail. "We appreciate the enthusiasm local mountain biking groups have for riding in Yarra Bend and the long standing ties they have with the area," Mr Sullivan said.

"Whilst illegal trail building can damage sensitive ecosystems, Parks Victoria is managing the issue and its associated impacts in collaboration with the community while still providing a great recreational opportunity Penalties for making and riding on illegal tracks in the park start at $178 and rise into the thousands. Parks Victoria said it preferred to avoid a "zero-tolerance compliance strategy" in favour of working with riders to limit the activity to one track. Mr Kelly opposes that approach and wants to see riders fined. "Education and collaboration only goes so far and you need fines and proper deterrence to stop people misbehaving. You need to enforce the laws," Mr Kelly said.

"If you don't enforce the laws then you're saying those laws don't matter. "Parks Victoria needs to step up and protect out parks. It needs to be properly funded to do a proper job." A 2001 report by Parks Victoria into Yarra Bend Park's trail management found there were "four dirt trails where soil conditions allow the use of mountain bikes". However, less than 20 years later, Parks Victoria's position is that there should only be one track where mountain biking is allowed. The 2001 report found "some areas of the park now have an excessive number of trails", a problem which endures to this day.

It's understood a lack of resources hasn't helped Parks Victoria tackle the problem. A group of mountain bike riders has been trying to engage Parks Victoria in collaborating on maintenance, replenishment and regulating the tracks for years. They are aware that rogue riders who build jumps and tracks and continue to ride them are giving the riding community a bad name. Some in the group accept mountain biking in the park should be restricted to just the one track and are happy to share that trail with all other user groups. They will also help maintain the trail. "We don’t ride it if it’s wet. We don’t want any disturbance on the soil at all," one of the riders, John Desmarchelier, said. Mr Desmarchelier was recently taken on a tour of the park by one of its rangers to better understand the cultural and environmental significance of the area.