Artikkelit jotka sisältää sanan 'Finland'

The carbon pool of surface layers (up to 500 years old) in 73 boreal mires was investigated in order to assess its significance in the carbon cycle. Peat columns were collected from mires of varying depth, age and degree of natural state in the aapa mire and raised bog regions and coastal mires of southern and central Finland and Russian Karelia. The quantities of carbon sequestered during recent centuries and over the entire lifetimes of the mires were determined using a total of 367 dates (186 14C AMS and 181 conventional dates) and age-depth models derived from bulk density measurements. Particular attention was paid to accumulation over the last 100 and 300 years, as these periods encompass the best estimates of the acrotelm age across the range of sites investigated. The average carbon pool of layers younger than 300 years was determined as 101 ± 8 tonnes ha-1 in the aapa mire region, 115 ± 9 tonnes ha-1 in the raised bog region and 184 ± 20 tonnes ha-1 in coastal mires. Overall, the mean carbon pool of layers younger than 300 years was calculated to be 121 ± 7 tonnes ha-1 (range 44–259 tonnes ha-1) and of layers younger than 100 years 63 ± 4 tonnes ha-1 (range 17–141 tonnes ha-1). The size and dynamics of the carbon pool represented by these surface layers depends upon the mire site type, vegetation and natural state; variations reflect differences in plant communities as well as factors that affect biomass production and decay rates. The high carbon accumulation in surface layers is temporary and mainly related to the development of the mire. The surface layers are still undergoing a rapid carbon cycle. A relatively rapid accumulation and turnover of carbon is taking place in surface layers (<300 years) in the same way as in a growing forest. Therefore, this "pre-peat" in the surface layers of mires should be distinguished as a separate class from the peat underneath. Our results indicate how important it is to understand the carbon accumulation rates of surface layers and the long-term dynamics of mire carbon accumulation in order to set the current flux estimates in perspective.

• Mäkilä, Geological Survey of Finland, P.O. Box, 96, 02151 Espoo, Finland Sähköposti: ei.tietoa@nn.oo
• Goslar, Sähköposti: ei.tietoa@nn.oo

Nineteen words, describing different types of mires and morphological and topographical features in mires, used in the dialects of northern Finlad are described in this article. Several of these words have been adopted from the indigenous Sami people, who live in the northernmost part of Finland, Sweden and Norway. Best known of these Sami words are aapa and palsa, which are internationally used mire terms. Key words: dialect, loan words, mire words, North-Finland, Sami language

• Aapala, Research Institute for the Languages of Finland, Sörnäisten rantatie 25, FIN-00500 Helsinki, Finland Sähköposti: ei.tietoa@nn.oo
• Aapala, Sähköposti: ei.tietoa@nn.oo

The study was made in four experimental fields on drained peatland in western Finland (63-66°N). One of the experiments was laid out in 1972; the others in 1978-1979. Treatments included different kinds of wood ash and PK-fertilizer, an ash-imitating mixture and apatite+biotite. Needle analyses and growth measurements were carried out in 1983— 1986. The concentrations of Mg and Mn generally decreased after fertilization. A rise in the foliar P, foliar K and foliar weight correlated with the growth response. Best growth increment was achieved with the ash-imitating mixture and PK-fertilizer, while apatite+biotite did not increase growth. In the first years after fertilization, growth on the ash plots was weaker, but later stronger or equal to growth on PK- and ash-imitating plots. The correlation between initial tree height and post-fertilization growth was similar on the different treatments. The poor growth increment on some ash treatments was probably due to the insufficient amount of nutrients in the ashes used. Key words: Ash fertilization, Finland, growth, needle analysis, peat, Scots pine

• Silfverberg, The Finnish Forest Research Institute, P.O. Box 18, SF-0I301 Vantaa, Finland Sähköposti: ei.tietoa@nn.oo

Because of the lack of hydrocarbon fuels in the Finnish territory, peat plays a very important role as an indigenous energy resource. Some 5 per cent of the area of Finnish mires is estimated to be suitable for industrial peat harvesting. This area contains so much peat that at the present consumption rate it would suffice for 400 years. In the foreseeable future industrial peat use, most of which will be for energy production purposes, could grow by 50-100 per cent compared with present use. Such development will depend, however, upon economic competition from other energy sources and pressure related to the environmental aspects of peat harvesting and use. Keywords: Energy, Finland, future developments, peat

• Sahrman, Association of Finnish Peat Industries, Kuokkalantie 4, SF-40420 Jyskä, Finland Sähköposti: ei.tietoa@nn.oo

The first regional division of Finnish peatlands was purposed by A.K. Cajander in the beginning of the century. It was based on vegetation, mire morphology, and landscape topography. The division was, however, difficult to compare with forest vegetation regions. As a result Prof. Aarno Kalela, in the 1950s, organized a study concerning the regionality of peat-land vegetation; the field work for which was performed by the authors as students. In this new division mire complex types and their regions were determined on the basis of vegetation but named according to mire morphology. The ecological approach to Finnish mire types also made it easier to compare them with peatland vegetation world-wide. Keywords: Historical review, mire complex types, Finland

• Eurola, Department of Botany, University of Oulu, Linnanmaa, SF-90570 Oulu, Finland Sähköposti: ei.tietoa@nn.oo
• Ruuhijärvi, Sähköposti: ei.tietoa@nn.oo

The results of a survey of 254 random sample plots, each 1 km2 in area and covering 1 543 km of mire transect line are reported. 74% of the peat-land encountered were drained with open ditch networks for forestry purposes. Of those 19% were classified as recently drained, 66% as transitional, 10% as transformed peat-moor peatlands, and 5% as being under the influence of nearby drainage. Drainage activity had been most often carried out on spruce mires, pine bogs, combination types, and rich fens and to a lesser extent on poor fens/bog hollows. The nutrient status and peat thickness had been taken into account only to a limited extent although ombrotrophic peatlands had been drained to a lesser extent than rich peatlands. There was an increasing tendency to extend drainage activities to thick, ombrotrophic mire types. 17% of peatland under the influence of drainage (750 000 ha) are unsuitable for forestry purposes. Considered within each unsuitable mire type more than 50% of their area is drained. Keywords: Drainage, Finland, mire types, peatland

• Eurola, Department of Botany, University of Oulu, Linnanmaa, SF-90570 Oulu, Finland Sähköposti: ei.tietoa@nn.oo
• Aapala, Sähköposti: ei.tietoa@nn.oo
• Kokko, Sähköposti: ei.tietoa@nn.oo