6000 years of forest dynamics in suserup skov, a seminatural Danish woodland

摘要

The history of a forest stand over the last 6000 years has been reconstructed by studying pollen, macrofossils and charcoal from a small, wet hollow in Suserup Skov on the island of Sjaelland in eastern Denmark. The earliest recorded forest was Tiliadominated but contained an intimate mixture of many different tree species that included Acercampestre, A. platanoides, Alnus glutinosa, Betula pubescent, Corylus avellana, Frangula alnus, Fraxinus excelsior, Malus sylvestris, Populous tremula, Pinus sylvestris, Quercus robur, Q. petraea, Salix spp., Sorbus aucuparia, Tilia cordata and T. platyphyllos. The preserved fruits of T. platyhyllos confirm its hitherto doubtful status as a native member of the Danish flora. The present-day woodland developed after a period of intensive anthropogenic disturbance between approx = 600 BC and AD 900, during which time open canopy conditions prevailed at Suserup. Fagus sylvatica and Fraxinus excelsior are the dominant trees at present, together with some Quercus robur and Ulmus glabra. Charcoal was present in the sediments from most time periods except at the Ulmus decline In the last 1000 years of the sequence - the period of Fagus dominance - charcoal counts were consistently low. Pinus sylvestris was a natural component of this primarily deciduous forest, and the last macrofossil fites from c. AD 900. Macrofossil Pinus cone scales recorded c. AD 1800 originate from planted individuals. Prior to Fagus dominance, the forest had an open structure partly caused by frequent, low-intensity firsts associated with the presence of Pinus sylvestris. The replacement of Tilia by Fagus in this forest was catalysed by human activity. If the forest had not been so disturbed, the rich diversity of trees would most probably have persisted up to the present time, with only a moderate-sized Fagus population.