Northern boreal forest ecosystems are predicted to experience more frequent summer droughts in the future. The majority of Swedish forest are secondary forests that are managed commercial forests with little diversity in species and structure. Only a small part is made up of primary forests that have experienced limited direct human impact. So far, it has not been known how primary forests and managed secondary forests react to drought. In a new study published in the scientific journal Environmental Research Letters, a team of researchers led from Lund, analysed how the drought of 2018 affected the forest types.
“We used a unique map of primary forests in Sweden and investigated whether there might be any difference in how these forests and neighbouring secondary forests were affected by the drought in 2018. The results showed that secondary forests in Sweden were more affected by the drought than primary forests were,” says Anders Ahlström, researcher in physical geography at Lund University. In the study, researchers used satellite images and a map detailing more than 300 primary forests in Sweden. By analysing a high-resolution vegetation index over these and the buffer zones surrounding the primary forests, which represent secondary forests with a similar environment and drought situation in summer 2018, the research team were able to gain a picture of how the dry summer hit the different forest types.
