The core areas of the Siebengebirge region are highly biodiverse as a result of their geology and climate. The Siebengebirge hills alone are home to some 730 plant species in an area of only 4,800 ha. The project region is characterised by locally typical and nationally representative deciduous forests (Luzulo-Fagetum and Asperulo-Fagetum beech forest; limestone beech forest of the Cephalanthero-Fagenion; Stellario-Carpinetum and Galio-Carpinetum oak-hornbeam forest; and Tilio-Acerion forest of slopes, screes and ravines) of the Siebengebirge and Leuscheid region with the black stork as the flagship species, the sparse orchards that are a product of the cultural heritage of the Pleiser Hügelland region with breeding populations of little owl, and the large areas of rocky and steep habitats that mark the northern limit to the range of nationally threatened species such as wall lizard. The outstanding natural endowment of the core areas is complemented by near-natural rivers, streams and forest springs. The project area is home to one of the largest populations of yellow-bellied toad in the state of North Rhine-Westphalia. The area is also unique in being home to populations of both the scarce large blue and the dusky large blue butterfly and of both European crayfish and stone crayfish.

An in-depth regional consultation process is underway to agree the detailed project objectives and measures.