Extension of a guide for the identification of forest sites: use of National Forest Inventory data. An example of application to the borders of the "Gâtinais Oriental"

Abstract

The IFN (French National Forest Inventory) floristic and ecological data were used to extend the validity area of a guide for forest types identification. The studied case concerned the «Gâtinais oriental» and «Puisaye des plateaux» added to the «Pays d'Othe» and the «Champagne sénonaise». With a bibliographic study, phytoecological surveys realized during the the development of forest types catalogues by Cemagref and new surveys in «Gâtinais oriental», IFN data allowed to :- reveal the similarity between the regions ;- specify the frequency and diversity of ecological characteristics, particularly trophic and hydrous features, in each region. The IFN data are as rich in information as those of the initial catalogues. In all, 1852 phytoecological data were gathered in a database. Their representation in ecograms (acidity and soil humidity) appeared to be much more pertinent than the only example-types published in the initial catalogs in order to give useful information about the possibility of extension of the validity of the guide in the four regions.