Knettishall Heath is a 91.7 hectare biological Site of Special Scientific Interest west of Knettishall in Suffolk. A larger area of 176 hectares is the Knettishall Heath nature reserve, which is managed by the Suffolk Wildlife Trust.
Suffolk Wildlife Trust (SWT) describes itself as the county's "nature charity – the only organisation dedicated wholly to safeguarding Suffolk's wildlife and countryside." It is a registered charity, and its headquarters is at Brooke House in Ashbocking, near Ipswich. It was founded in 1961, and is one of 47 wildlife trusts covering the Great Britain and Northern Ireland. As of March 2017, it has 13,200 members, and it manages 3,120 hectares of land in 60 nature reserves, most of which are open to the public. It had an income of £3.9 million in the year to 31 March 2017.
Hayley Wood is a 51.7 hectare biological Site of Special Scientific Interest south-east of Great Gransden in Cambridgeshire. It is a Nature Conservation Review site, Grade 1, and it is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.
Lackford Lakes is a 105.8 hectare biological Site of Special Scientific Interest (SSSI) north and east of Lackford in Suffolk. The SSSI is part of the 131 hectare Lackford Lakes nature reserve, which is managed by the Suffolk Wildlife Trust.
Newbourne Springs is a 15.7 hectare biological Site of Special Scientific Interest in Newbourne in Suffolk. It is owned by Anglian Water and managed by the Suffolk Wildlife Trust.
Groton Wood is a 20.2 hectare biological Site of Special Scientific Interest north-east of Groton in Suffolk. It is owned and managed by the Suffolk Wildlife Trust.
Bradfield Woods is an 81.4 hectare biological Site of Special Scientific Interest between Bury St Edmunds and Stowmarket in Suffolk. The site is in three separate blocks, the adjoining Felsham Hall and Monkspark Woods, and the much smaller separate Hedge Wood and Chensil Grove. Felsham Hall and Monkspark Woods are designated a 63.3 National Nature Reserve, also called Bradfield Woods, and are managed by the Suffolk Wildlife Trust.
Mickfield Meadow is a 1.9 hectare biological Site of Special Scientific Interest north of Mickfield in Suffolk. It is managed by the Suffolk Wildlife Trust.
Bonny Wood is a 20 hectare nature reserve east of Barking Tye in Suffolk. It is managed by the Suffolk Wildlife Trust. The site is part of the Barking Woods biological Site of Special Scientific Interest.
Combs Wood is a 15.1 hectare biological Site of Special Scientific Interest on the southern outskirts of Stowmarket in Suffolk. It is owned and managed by the Suffolk Wildlife Trust.
Cornard Mere is an 8.5 hectare biological Site of Special Scientific Interest in Little Cornard in Suffolk. It is managed by the Suffolk Wildlife Trust.
Sizewell Marshes is a 105.4 hectare biological Site of Special Scientific Interest adjacent to Sizewell in Suffolk. It is in the Suffolk Coast and Heaths Area of Outstanding Natural Beauty, and is part of a 144 hectare nature reserve managed by the Suffolk Wildlife Trust as Sizewell Belts.
Monewden Meadows is a 3.7 hectare biological Site of Special Scientific Interest south-west of Monewden in Suffolk. It is a Nature Conservation Review site, Grade I, and it is managed by the Suffolk Wildlife Trust under the name Martins' Meadows.
Hopton Fen is a 15.3 hectare biological Site of Special Scientific Interest north of Hopton in Suffolk. It is managed by the Suffolk Wildlife Trust.
Metfield Meadow is a 1.3 hectare biological Site of Special Scientific Interest west of Halesworth in Suffolk. It is owned and managed by Suffolk Wildlife Trust under the name Winks Meadow.
Barking Woods is a 98.7 hectare biological Site of Special Scientific Interest in six separate blocks north-east of Ipswich in Suffolk. Part of it is a 20 hectare nature reserve called Bonny Wood, which is owned and mangaged by the Suffolk Wildlife Trust.
Weston Fen is a 49.7 hectare biological Site of Special Scientific Interest in Hopton in Suffolk. It is part of the Waveney and Little Ouse Valley Fens Special Areas of Conservation, and an area of 37 hectares is managed as a nature reserve called Market Weston Fen by the Suffolk Wildlife Trust.
Thorpe Morieux Woods is a 45.2 hectare biological Site of Special Scientific Interest north of Thorpe Morieux in Suffolk. Part of it is Bull's Wood, a nature reserve managed by the Suffolk Wildlife Trust.
