Conceptual scheme of the multi-tiered approach. The four boxes in the scheme correspond to the four subsections below. 

 
  Part of: Nedkov S, Nikolova M, Prodanova H, Stoycheva V, Hristova D, Sarafova E (2022) A multi-tiered approach to map and assess the natural heritage potential to provide ecosystem services at a national level. One Ecosystem 7: e91580. https://doi.org/10.3897/oneeco.7.e91580