Police are treating the blaze which broke out in a field and burnt nearly two hectares near the Ravenswood estate in Ipswich as a suspected arson.
Suffolk Fire and Rescue Service crews were called to Ravenswood Park, near Fen Bight Circle, at about 7.50pm on Monday.
Engines from Ipswich East, Princes Street, Newmarket and Felixstowe stations were dispatched to the scene.
A stop was called by the fire service shortly before 9.30pm.
A Suffolk police spokesman confirmed officers believed the fire was started deliberately and are treating the incident as an arson.
However, no arrests have been made in connection with the blaze so far.
Drone pictures taken after the blaze, which spread close to nearby homes, revealed the land in the park had been left scorched.
The incident came amid sweltering conditions on Monday, with temperatures reaching 38.1C in Santon Downham in west Suffolk.
An investigation into the blaze has been launched by the fire service, but a cause is yet to be established.
Sarah Barber, who represents Priory Heath at Ipswich Borough Council, revealed Ravenswood Park is popular with skylarks.
According to the RSPB, the UK's skylark population halved during the 1990s and is still declining. In the preferred habitat of farmland, skylarks declined by 75% between 1972 and 1996.
Mrs Barber said: "I have spoken to the head of the parks department, and they will be going on to assess the damage.
"The park is a really good area that skylarks nest in. We're hoping the fire hasn't had too much on an effect on them – it's an important habitat.
"I would like to say thank you to all of the firefighters who were doing an amazing job. Thankfully no one was hurt."
The damaged area will be left for the summer says Ipswich Borough Council as it begins work to rectify the fire damage and protect the park's wildlife.
A council spokesman said: "The Council is disturbed by the ecological damage caused by Monday's fire at Ravenswood Park. The burning of two hectares of semi-natural habitat in the height of summer, will have killed many invertebrates, plants and impacted the habit of ground-nesting birds, reptiles and small mammals. The fire does not seem to have affected the skylarks that would have been nesting nearby.
"The damaged area will be left for the summer. In autumn, in conjunction with the local community and wildlife groups, further skylark plots will be created by turning the soil to remove the fire-damaged thatch area and then undertake some seeding with sandy soil wildflower species, such as birds foot trefoil for pollinators."
Anyone with information related to the incident is urged to contact Suffolk police, quoting reference 420 of July 18.
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