Förändringen av tall- och granbestånden i eklandskapet söder om Linköping, 1927 jämfört med 2013

Sammanfattning: The aim of the study was to compare how the population of pine (Pinus sylvestris) and spruce (Picea abies) have changed between 1927 and 2013 in the oak landscape south of Linköping. A field study was carried out in 22 two kilometre lines which also had been studied in 1927. In these lines, which where ten meters broad and had a direction from west to east, the pines and spruces were counted, measured and classified by steam diameter. The obtained result was that the basal steam area (m²/ha) had increased for pine (44%) and spruce (57%) between 1927 and 2013. The amount of trees had increased in all diameter classes except thinner pine and spruce with a diameter of 5-10cm. The increase for pine in the three largest diameters (35-40cm, 40-45cm and >45cm) was 34%, 96% and 297%, respectively, and for spruce 221%, 508% och 400%. The reason why young pine had decreased since 1927 can be increased browsing by moose (Alces alces), a decline in natural rejuvenation, or the large-scale change in forest management since 1927.