Future forest distribution on Finnmarksvidda, North Norway

Abstract

Finnmarksvidda is Norway’s largest mountain plateau, located in the Arctic/alpineboreal transition area. The area is also a central winter grazing area for the reindeer herds of the indigenous Sámi people. This study develops a bioclimatic-based model to simulate future potential vegetation, with a focus on forest types. The model utilizes a bioclimatic study in the region, where vegetation types have been grouped according to minimum summer temperature demands. This is then used as a base for modelling of future vegetation. Due to the flat landscape of Finnmarksvidda, the model shows that a 1°C increase in summer temperatures will potentially lead to an increase of forested areas by 4485 km2, which is a 70% increase from the current 6900 km2 to a simulated 11 706 km2. This in turn will lead to a reduction of Arctic-alpine heaths from 4440 km2 today to potentially only 670 km2. Such changes will have consequences for the reindeer grazing system, as the predicted changes will lead to a decrease in the vegetation types that have high winter grazing accessibility for reindeer, from 2386 km2 today to potentially only 377 km2. On the other hand, vegetation types with medium accessibility will experience an increase, from 2857 to 3366 km2.