A comparison between the diaspore bank and above-ground bryoflora in the beech forests of Navarra (Northern Spain)

Bryophyte diaspore banks remain poorly known, especially those from Atlantic forests. Here we describe the composition and characteristics of diaspore banks in Atlantic beech forests (Fagus sylvatica) (Navarra, Northern Spain) and compare them with above-ground vegetation. Soil samples from nine beech forests were cultivated for eight-nine months and germinating species were identified; we also collected above-ground bryophytes in the same beech forests. The diaspore bank has 40 species, and there is strong positive correlation between the floristic richness in the diaspore bank and in the corresponding above-ground vegetation. The specific composition of the two ecological compartments is very different; only Fissidens taxifolius and Polytrichum formosum are always frequent. Some species in diaspore bank are very uncommon in above-ground vegetation (Pohlia andalusica, Trichodon cylindricus); we postulate that some species are dispersed over a long distance. Colonist species are the most frequent in the diaspore bank, while perennials dominate in above-ground vegetation. This contrast is reduced in acidophytic beech forests, mainly due to the high number of colonist liverworts in the above-ground vegetation.