text: Selection and conservation Sites notified for their biological interest are known as Biological SSSIs (or ASSIs), and those notified for geological or physiographic interest are Geological SSSIs (or ASSIs). Sites may be divided into management units, with some areas including units that are noted for both biological and geological interest.
  Biological
  Biological SSSI/ASSIs may be selected for various reasons, which for Great Britain is governed by published SSSI Selection Guidelines. Within each area, a representative series of the best examples of each significant natural habitat may be notified, and for rarer habitats all examples may be included. Sites of particular significance for various taxonomic groups may be selected (for example birds, dragonflies, butterflies, reptiles, amphibians, etc.)—each of these groups has its own set of selection guidelines.
  Conservation of biological SSSI/ASSIs usually involves continuation of the natural and artificial processes which resulted in their development and survival, for example the continued traditional grazing of heathland or chalk grassland.
  In England, the designating body for SSSIs, Natural England, selects biological SSSIs from within natural areas which are areas with particular landscape and ecological characteristics, or on a county basis. In Scotland, the designating authority is NatureScot; the role in Wales is performed by Natural Resources Wales (formerly the Countryside Council for Wales). In the Isle of Man the role is performed by the Department of Environment, Food and Agriculture.