Field studies and in-situ monitoring: 54 sites, approximately 5,300 ha were used as the basis for the analysis.
Over the period 2000-2010, more than 210,000 pieces of data were compiled in the database for the surveyed groups, which have the following distribution:
|Insects (Butterflies, Dragonflies, Grasshoppers, Crickets)||11,245|
The data was verified, supplemented and adjusted before being processed for presentation using resources recognised by the scientific community at a national, regional and European level: these resources included lists of protected species, European red lists, and notably rarity coefficients.
The data was finally assembled into a state of knowledge study report (1) and a cartographic atlas comprising nearly 800 maps.
The criteria used to determine the heritage value of species include:
(1) Eden 62, 2013 “État des connaissances de la biodiversité des Espaces Naturels Départementaux du Pas-de-Calais (2000-2010)”, Biotope, 252 pp. Document can be consulted in French only in the “espace pro” of Eden 62’s website (www.eden62.fr)