Although you will find different definitions of gap analysis as you read through some of the web sites linked to below, the basic principle of gap analysis is moderately simple. The ownership map will be a mosaic of publicly owned land and land under private ownership. Take the three acetate maps and lay them on top of each other and look to see if the distribution of the plant or animal species is primarily contained within conservation lands or in lands under private ownership and not protected. One solution would be to try to buy some of the critical land parcels to form protected areas for the species.
Many species occur primarily in particular vegetation types.
If the distribution of a plant or animal species falls in a particular vegetation site, one could say that vegetation type is a critical component in any conservation plan to protect that species. A conservation plan would be to try to buy private parcels of that vegetation type for the conservation of the designated species. Of course, things rapidly become more complex than this simple example because many species are involved in any realistic conservation effort. Currently most emphasis is on vertebrate species, although the principle applies equally to any group of plants and animals. National Gap Analysis Program .