New charges at the Winding Walks

Car parking charges have recently been introduced at the Wioding Walks (Whiteash Hill) in Fochabers, along with many other FCS sites. I gather than there has been an increase from 23 - 45 of the 326 sites which charge for parking recently. There are fantastic mountain bike tracks here and maintenance of the facility clearly costs money. But somehow it doesn't sit easily with me to see signs like this in a site managed by the public body with a mission ' to protect and expand Britain's forests and woodlands and increase their value to society and the environment.' I wonder how much less revenue would be collected if they asked for a voluntary donation of a recommended amount instead of a charge?