Suffolk Wildlife Trust creates large reserve at Leavenheath
Conservationists have raised £110,000 to buy 76 acres of fields to create a much larger reserve.
Suffolk Wildlife Trust is to purchase Fords Heath near Leavenheath, next to its existing Arger Fen and Spouse's Vale reserves.
It will now restore the land to grassland, known as "furzey commons", for animals including dormice at the site between Sudbury and Nayland.
The fundraising appeal was made to add to a legacy left to the trust.
The trust said the aim of the scheme was to link up protected parcels of land so that habitats could be managed and species such as the dormouse could move between them.
Julian Roughton, chief executive of the trust, said: "Buying and enlarging nature reserves is one of the most powerful ways in which we secure a better future for wildlife.
"As the habitats mature it will become a haven for wildlife and a place for people to cherish."
The total cost of the buying Fords Heath was undisclosed, but the legacy came from Gerald Ford, a trust member from Essex.
His brother, Geoff Ford, said: "Gerald loved Suffolk - the county of his parents - and always wished to leave some permanent presence here.
"He was a life-long naturalist and would have been delighted to see his legacy being used to create a space for wildlife."