Combining historical and ecological data: Impact of past population history on forest structure and fungal diversity in Russian Karelia

Before 19th century, the impact of forest industry on forests of Russian Karelia was minimal, and, in the first half of the 20th century, very large areas of western taiga remained beyond the limit of economic profitability of timber industry. However, the Karelian people populated the boreal forests of Karelia and their villages had spread all over the region. The livelihood of these villages based largely on small-scale farming including slash and burn agriculture. In addition, in the cold northern climate, the firewood was extracted from forests in very large quantities. In the political turmoil of 20th century Russia, the significant part of remote villages were decimated, but their impact on landscape and forest structure remains. We have been able to combine the information about the location and population size of historic villages and forest structure. We used two large areas of ancient landscape as case studies, in order to demonstrate that the signs of land use of past human populations are still visible in the forests of Karelian Republic, Russian Federation. These areas were Kostomuksha Strict Nature Reserve and Kalevala National Park in the west and Vodlozero National Park in the east. From the western area, we collected field data about the forest structure and presence of fungi. From the eastern area, we used forest inventory data. The stand age, and diversity of dead wood increased with the distance from the old villages (0-2 km). In very large scale (0-20 km), human impact may have changed the tree species composition favoring fire tolerant pine over less tolerant spruce. In general, the fungal diversity has recovered after the abandonment of the villages in nearby forests. However, we found that the rare wood inhabiting fungi had not been able to colonize forest stands with the same rate of the common species. We conclude that the current forest landscape of Karelia composes of different layers of historic and more recent forest use activities of the society. It is obvious, that we need to incorporate all these layers, if we wish to understand the present pattern of the forest biodiversity. Moreover, landscapes that are shaped by historic human activity but are preserved from recent industrial forestry, i.e. historic landscapes, may serve as “living archives” for various ecological research. For example, as source of information about the ability of forest ecosystem functions or properties to recover from disturbance, e.g. recovery of stand and tree species structure, carbon balance of soils, species diversity and trophic webs. This kind of information may be most valuable when modern society tries to find the ways to mitigate the adverse effects of environmental change of the 21st century.peerReviewe