Trente ans plus tard… les fourmis rousses des bois, toujours un bon indicateur de l’état de conservation des forÊts de montagne?

Abstract

The Formica rufa group of species is considered to be a good indicator of the state of conservation of montane forests. The standardised protocol for tracking myrmecological populations developed by Torossian in 1983 is re-examined thirty years onwards at the same site using measurements of the myrmecological population of a montane forest in the Pyrenees. Results show that the density of domes has dropped drastically. We hypothesize that the density of ski runs, the contrasts between different-facing slopes, and the type of forest stands may explain these variations. Considering the life expectancy of Formica rufa populations, this study underscores the importance of diachronic analyses like these for the purpose of long term monitoring of forest ecosystems.