The South Exmoor SSSI is smaller, covering and including the River Barle and its tributaries with submerged plants such as alternate water-milfoil (Myriophyllum alterniflorum). There are small areas of semi-natural woodland within the site, including some which are ancient. The most abundant tree species is sessile oak (Quercus petraea), the shrub layer is very sparse and the ground flora includes bracken, bilberry and a variety of mosses. The heaths have strong breeding populations of birds, including whinchat (Saxicola rubetra) and European stonechat (Saxicola rubicola). Wheatear (Oenanthe oenanthe) are common near stone boundary walls and other stony places. Grasshopper warbler (Locustella naevia) breed in scrub and tall heath. Trees on the moorland edges provide nesting sites for Lesser redpoll (Acanthis cabaret), common buzzard (Buteo buteo) and raven (Corvus corax).