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Hokkanen T.J., Yakovlev E., Vuorio V., Arnold K., Salovaara K. & Tietôvôinen M.
Fragmentation as a factor changing forest biodiversity
// Biodiversity of Fennoscandia (diversity, human impact, nature conservation). Petrozavodsk: Karelian Research Centre of RAS, 1997.
Declining total area of natural forests is the fundamental reason to decrease of biodiversity in forests' ecosystems in Finland. In Southern part of Finland only 2 % of the forests are over 140 years old. Not only decreasing total area but also decrease of forest units -- fragmentation -- is threatening forest organisms. Three basic principles can be applied to fragmentation: 1)size of the individual forests decreases, 2)size of different forest stands within the forest decreases, and 3) isolation (distance between) forest stands increases. In this process the edge effect grows more intense, and the quality of habitats changes more than can be expected according to the decrease in area.
Eastern Finland's forested areas have changed greatly within last 50 years. Private land ownership together with Finland's flourishing forest industry have changed forests to mozaics of managed stands ranging from clearcuts to mature forests. In North Karelian biosphere reserve natural forest stands are very small, and far between. Russian Karelian forests, on the contrary, have been the latest 50 years state-owned, and especially near the Finnish border largely untouched due to the border regulations. This combination of untouched and fragmented forests near each other is unique, and offers an excellent opportunity to study the effects of fragmentation.
This presentation introduces the Finnish - Russian study of biodiversity which is conducted on both sides of the border. The Finnish study areas are in Ilomantsi and Lieksa; Russian counterpart is in Tolvajôrvi nature reserve. The study concentrates on three-dimensional work: firstly, the forest stands are described carefully as to living and dead trees, understorey vegetation and soils, and the adjacent areas are inventoried for their main land uses; secondly, representative transects are laid across the gradients reaching from cut areas to the heart of forests; these transects will be used for intensive measurements of microclimatic and biotic changes to detect quality and extent of the edge effect. Preliminary results from the first study period are given.
Eastern Finland's forested areas have changed greatly within last 50 years. Private land ownership together with Finland's flourishing forest industry have changed forests to mozaics of managed stands ranging from clearcuts to mature forests. In North Karelian biosphere reserve natural forest stands are very small, and far between. Russian Karelian forests, on the contrary, have been the latest 50 years state-owned, and especially near the Finnish border largely untouched due to the border regulations. This combination of untouched and fragmented forests near each other is unique, and offers an excellent opportunity to study the effects of fragmentation.
This presentation introduces the Finnish - Russian study of biodiversity which is conducted on both sides of the border. The Finnish study areas are in Ilomantsi and Lieksa; Russian counterpart is in Tolvajôrvi nature reserve. The study concentrates on three-dimensional work: firstly, the forest stands are described carefully as to living and dead trees, understorey vegetation and soils, and the adjacent areas are inventoried for their main land uses; secondly, representative transects are laid across the gradients reaching from cut areas to the heart of forests; these transects will be used for intensive measurements of microclimatic and biotic changes to detect quality and extent of the edge effect. Preliminary results from the first study period are given.
Last modified: November 30, 2006