One of the founders of the Friends of Poole Park has criticised the closure of an entrance to vehicles from today.
The Whitecliff Road and Twemlow Avenue entrance and exit is closed 24 hours a day for a trial period.
A four-week public consultation also begins today on whether to make it permanent.
BCP Council says reducing traffic in the park could benefit both users and wildlife.
But Bob Lister says it will hit the most vulnerable.