There's been a large increase in the number of bees in the South Downs National Park.
It follows the introduction of projects to grow wildflower meadows.
A 72% rise in recorded bee populations and other pollinators has been recorded.
The national park, which stretches from Winchester in Hampshire to Eastbourne in East Sussex, launched the Bee Lines project three years ago to create network of wildflower corridors to encourage the "vital ecosystem engineers".
The park said early reports show that biodiversity has improved in the new wildflower oases, with one area at Sompting in West Sussex recording "significant" increases.
Peter King, director of Ouse and Adur Rivers Trust, said: "The funding fromthe South Downs National Park Trust has allowed us to create 2.5 hectare of wildflower meadows on Sompting Brooks.
"Since sowing the seeds, the field has seen exceptional growth and diversity of species. It's too early to attribute any specific species or biodiversity increase specifically to this meadow habitat; however, we have recorded a 72% increase in pollinator species using the site since the arable fields were reverted to meadow.
There's also been an overall species diversity increase of 98% of monitored species, including birds, bats, reptiles, invertebrates, and small mammals.
Peter said, "Overall species records from the site have increased from 179 to 624 sincethe project as a whole was completed."
The South Downs National Park Trust has provided 11 grants in recent months to create wildflower areas at farms, community fields, recreation grounds and road verges, with a further eight projects receiving funding last year from a total of £75,000 raised for the scheme.
Nick Heasman, who leads Bee Lines, said: "It's wonderful to see this wildflower planting making a significant difference to biodiversity, and that effect can only multiply in future years as the habitat becomes more established.
Bees are vital ecosystem engineers and it's so important we try to halt and reverse their decline."