This document is conceived as a concept note, hoping to serve as a reference or inspiration for readers approaching the theme of coherence of the Natura 2000 Network for the first time. Its purpose is to create a concise conceptual body, and to demonstrate its feasibility by proposing an assemblage of techniques that converge towards an evaluation procedure. Conveying the operability of the ensemble has been considered a priority, as opposed to a detailed review of its components. In other words, the choice of techniques incorporated in each component of coherence is not exclusive, and alternative models can substitute the models presented here as long as they play an equivalent role in the final result. From this point of view, virtually no part of the document replaces an in-depth review of the subject, and bibliographical references have been reduced to the minimum necessary to ensure comprehension.

Faced with the need to specify and assemble a practical approach to the coherence of a conservation network such as Natura 2000, it seemed more logical to use a particular biogeographical region as an example, rather than to discuss general problems. The Macaronesian Region is unique in this respect, because its island dimension adds interesting theoretical opportunities, not only related to the persistence of habitats and species, but also to methodological aspects such as the relationship between spatial scale and size of the study area. However, even with this as a common thread, previous experience with the methods discussed in this and other regions is limited. This explains why many of the examples developed come from other biogeographical regions, and why this document should not be taken as a protocol for assessing the coherence of the Natura 2000 Network in the Macaronesian region in particular.

While the authors have made a special effort to explain the techniques in a concrete and reproducible way, this is less true for the administrative and managerial aspects. The reason is that the concept of network coherence can be given a theoretical basis, for the testing of which objective techniques can be specified. However, management, and particularly its interface with a technical component, is more of a heuristic problem than a theoretical one. In other words, a prototypical relationship between conservation policy-makers, managers and technicians must be established, establishing functional feedback between these three types of actors. This is easier said than done, as the interests and constraints of each type come from different worlds and logics. Therefore, interactions must be refined during the solution of a problem. The expected contribution of this paper is to provide seeds for such interactions, so that heuristic refinement can be achieved on a solid and explicit basis.