Officers are appealing for witnesses and anyone with information to come forward after an arson attack at Oakdene Forest, St Leonards.
The incident happened around 12.30pm on Saturday 7 March 2015 when an area of around 30 square metres was set on fire.
A witness saw flames coming from the undergrowth and spotted two boys running from the area. The witness challenged one boy, who bit the witness on the hand and cycled away.
Dorset Fire and Rescue Service attended the scene.
The first boy is described as white, around 13 years old, five feet three with straight red hair, blue eyes and freckles on the face. He was wearing a blue denim jacket, black tracksuit bottoms with a white stripe on both legs and wellington boots. He was riding a black Apollo mountain bike.
The second is described as white, around 13 years old, with blond short hair with a side parting. He was wearing a blue Nike jumper, black trousers or jeans and green Wellington boots. He had a white mountain bike with red reflectors.
Police Constable Simon Fricker, of East Dorset police, said: “This incident could have caused serious damage to wildlife habitats in the vicinity.
”I would like to speak to anyone who may have seen two boys running from the area at the time, or anyone who may be able to identify the two described so they can assist me with my enquiries.”