A Sunshine Coast environmental group has launched a petition to protect a bushland reserve it says is under threat if the proposed Queensland Air Museum expansion goes ahead.

The Wildlife Preservation Society of Queensland - Sunshine Coast and Hinterland is countering the museum's petition to extend its footprint to house more aircraft and construct buildings.

The Caloundra museum's petition, sponsored by Member for Caloundra Mark McArdle, seeks to extend its current leased land on Pathfinder Dr into the Isabel Jordan Bushland Reserve next to Caloundra Rd.

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But the WPSQ says the museum should not expand into the reserve as it contains one of the last remaining Coastal Heaths in the region and is named in honour of a local icon.

"Half of it is bushland reserve, and it's all important wetland," branch secretary Jude Crighton said.

Ms Crighton said the museum should instead look to expand on the western side of its boundary to protect the four-hectare bushland reserve.

She said the reserve, which in 2008 was named after past WPSQ president Helen Isabel Jordan, contained vibrant and rare wildflowers like boronia.

"Only small patches of Coastal Heath remain between Caloundra and the Maroochy River, and the remaining areas need to be carefully managed to preserve the increasingly rare plants and animals they contain," she said.

"There's been so much of it cleared and there is so little of it left …"

WPSQ's Helen Kershaw said the group was not against the Queensland Air Museum's expansion, but hoped to work together to find a solution.

"We want to work with the air museum towards a better solution," she said.

Ms Kershaw said while Isabel Jordan was a "quiet and unassuming" person, she would be "waving her finger" if she knew the bushland reserve was under threat.

"She'd be out here with a placard," she said.

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Earlier this month, Queensland Air Museum president Cameron Elmes and volunteers said a petition was the next best move after many years of "going backwards and forwards" with Sunshine Coast Council and State Government.

"It could be a great loss to the Sunshine Coast and Queensland (if we can't expand)."

The WPSQ's counter petition has gained more than 800 signatures since it was launched on Wednesday. For more information, view the petition here.