Exmoor - Ecology

Ecology

In addition to the Exmoor Coastal Heaths Site of Special Scientific Interest (SSSI), two other areas are specifically designated. North Exmoor covers 12,005.3 hectares (29,666 acres) and includes the Dunkery Beacon and the Holnicote and Horner Water Nature Conservation Review sites, and the Chains Geological Conservation Review site. The Chains site is nationally important for its south-western lowland heath communities and for transitions from Ancient woodland through upland heath to blanket mire. The site is also of importance for its breeding bird communities, its large population of the nationally rare Heath Fritillary butterfly (Mellicta athalia), an exceptional woodland lichen flora and its palynological interest of deep peat on the Chains.

The South Exmoor SSSI is smaller, covering 3,132.7 hectares (7,741 acres) 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 African Stonechat (Saxicola torquata). 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 Redpoll (Acanthis flammea), Common Buzzard (Buteo buteo) and Raven (Corvus corax).