Banco de semillasdiversidad en bosques autóctonos y plantaciones forestales

Résumé

The aim of this work is to study the effect on the seed bank of the replacement of natural woodlands by deciduous (Larix kaempferi) or evergreen (Pinus radiata) coniferous plantations. At several areas of natural woodland and coniferous plantations, soil samples were taken in order to study the seed bank.The type of species found in the different seed banks were 5 tree and shrub species, 16 wide range herbaceous species and 14 herbaceous species typical of natural woodland. The highest number of seeds were found in the seed bank of larch plantations (655 seeds/m2), followed by the number in the seed bank of the pine plantations (405 seeds/m2) and finally by the number found in the natural woodland (312 seeds/m2). In the latter, the seed bank was mainly made up by Juncus spp. (40% of the total) and Rubus spp. (20% of the total) seeds. Within the seed bank of the P. radita plantations, Rubus spp. had the highest size (30% of the total), followed by the abundance of Cardamine pratensis (19% of the total) and finally by different species of Juncus spp. (12.7% of the total). In the larch plantations, the most abundant seeds belonged to the Juncus spp. species (20% of the total), however, there was not a clear difference among the rest. The similarity between the species present in the seed bank of the coniferous plantations and the natural woodland was around 80%.In conclusion, there is an urgent need for the maintenance of patches of natural woodland vegetation within the coniferous plantations in order to maintain the persistence of the diversity of the vegetation of natural woodland.