Pattern and process in south Swedish forests during the last 3000 years, sensed at stand and regional scales

1 Two palaeoecological data sets were used to study forest development in t he boreo-nemoral zone of southern Sweden during the last 3000 years. Maps o f forest types present in 1250 BC, AD 500 and today were compiled from regi onal pollen data and these were compared with 16 stand-scale pollen analyse s. 2 The forest type maps showed a transition from mixed deciduous forest to c oniferous forest consisting chiefly of Picea and Pinus. The stand-scale stu dies recorded the same general development despite site-specific trends. A detrended correspondence analysis displayed the successional trends of the stand-scale sites. All stands moved away from the rich deciduous forest rep resented by Alnus, Corylus, Quercus and Tilia via Betula and Carpinus to Pi cea and Pinus forest or, in two stands, to Fagus forest. 3 A rate of change analysis covering the last 3000 years showed that the ch anges recorded from the last 150 years were the most rapid, but represented the culmination of a transformation that was initiated 850 years earlier. These recent changes completely overshadowed the previous record. 4 The regional maps recorded relatively high proportions of Pinus in the ea stern part of the study area throughout the period under investigation. The stand-scale studies indicated that this area had a high fire frequency, wh ile the relatively recent increase in Pinus in south-west Sweden was better explained by anthropogenic influences. The stand-scale data suggested that the regional role of Pinus had been overestimated in southern Sweden 5 Corylus, Quercus and Tilia were the major species in the former forests, but began a slow decrease in importance around AD 700. The increasing cerea l pollen record was related to the decline of the deciduous forest componen t, suggesting that anthropogenic activity has been the major driving force in its loss. 6 The combination of regional- and stand-scale studies has provided new ins ights into forest pattern and process. The local records capture the essent ial features of the regional record of vegetation history, record forest co mposition more faithfully than regional sites, and additionally yield insig ht into processes such as fires that have a regional significance.