Response of an Atlantic heathland to experimental trampling

Trampling responses of an Atlantic heathland dominated by furzes were exper imentally determined. They concerned two levels of biological systems: the vegetal community level (community scale) and the species level (intracommu nity scale). Two trampling experiments were conducted: the first one was ca rried out in summer and the second one in winter. Heathland was trampled ov er 4 months, at differents intensities: 10, 30 and 90 persons a day. Whethe r trampling was conducted in the summer or in the winter, immediate respons es of heathland (community scale) were similar: resistance of this vegetal community did not vary with the trampling season. Responses also showed tha t there is no linear relationship between vegetation degradation and trampl ing intensity. Deferred vegetation responses were similar, but within the c ommunity heathland (intracommunity scale) responses of a taxonomic group ca n depend on the trampling season. For example, resilience of furzes trample d in winter was greater than resilience of furzes trampled in summer. Ali t hese results should be considered in order to establish management orientat ions of trampled heathlands. (C) 1999 Academie des sciences/Editions scient ifiques et medicales Elsevier SAS.