Almost all the SSSIs are within the High Weald area of outstanding natural beauty, and the scheme would also affect several ancient woodlands and the habitats of species of European importance, including dormouse and great crested newt.
The 352 hectares (870 acres) of woodland is said to be home to not only protected species such as the dormouse, but 75 species of birds, 23 species of native butterflies, the wild daffodil, wood anemone and enchanters' nightshade.