Diaspore bank of bryophytes in the holm oak ecosystem of the Bois d'Astros in Vidauban (Var, France)

Cultivation for 4 months, under controlled conditions, of 22 coresamples of soils (from the surface down to 3-4 cm depth) from each ofthe 3 stages of the dynamics of the holm oak (Quercus ilex L.) ecosystemat the bois d'Astros, near Vidauban (Var), shows that the edaphicdiaspore bank of bryophytes is about as rich in species as the surfacecommunities at the boring points (surface/soil bank, holm oak forest:8/8 species, Rosmarinus garrigue: 15111, Brachypodium phoenicoides lawn:11/12). It consists mainly of mosses, 50 to 58% of which are found onlyin the soil. Among these, the presence of oligotrophic species of openhabitats (Trichostomum brachydontium, Philonotis arnellii, Funaria grexmuehlenbergii and the liverwort Riccia sorocarpa) that occur belowground in the Quercus ilex forest is remarkable, whereas soil cores fromthe,garrigue and the lawn have given Bryum radiculosum andPseudocrossidium hornschuchianum which, like the 4 preceding taxa, arelacking in the above ground inventories (surface: 100 m(2)) carried outon the site in the holm oak ecosystem. Our results confirm that theproportion of acrocarpous mosses belonging to the colonist life strategytends to be more important below than above ground, whereas the reverseis true for pleurocarpous perennials. There is also an increase in thepercentage of colonists present in the soil, when passing from theforest to the garrigue and the lawn.