Lövskogens förändring i eklandskapet söder om Linköping : 1927 jämfört med 2013

The forests of Sweden are constantly changing. Map studies indicate that the amount of deciduous trees in Sweden has decreased in recent years in favor of the coniferous trees. The National Forest Inventory has since the early 1920s monitored the Swedish forests and in recent years has made the old data digitally available. In the present project, we have investigated how the numbers of stems in different diameter classes have changed for birch and other deciduous trees. The inventory was conducted in the same manner as in the first forest inventory. Ten meters wide transects, each two kilometers long, were inventoried from west to east in oak woodland south of Linköping. All trees breast-height diameter were measured in the transect and placed in nine diameter classes. The total number of stems per hectare for both birch and other deciduous trees had increased in area. The results of the inventory also show that the proportion of deciduous trees against conifers had increased by about ten percent for all diameter classes. The increased stem number, here documented in a small spatial scale, is in accordance with previous studies in Sweden. However, the other result differs from the hypothesis that deciduous trees should have decreased and pine trees increased. Based on previous studies in Sweden, conifers and especially spruce has increased. The increase of deciduous trees may be due to the investigation area that has historically been characterized by large areas of meadows and pastures. In the study area, there are a small number of landowners with large estates, who have been able to preserve the deciduous forest.