Articles containing the keyword 'peatland types'

A survey was carried out among forest foremen and forest technicians to record their observations on the value of various swamp and forest types as producers of berries and on the effect of drainage of peatlands upon the berry yields. Comparative agreement existed on the best blueberry (Vaccinium myrtillus L.) forest types and on the best lingonberry (Vaccinium vitis-idaea L.) forest types of rather dry upland sites. Fuscum pine swamps or fuscum bogs were considered best for the most part as regards the yield of cloudberry (Rubus chamaemorus L.). The replies showed rather great dispersion.

Agreement existed as well on the relation between drainage of peatlands and the yields of our economically most important swamp berries, cloudberry and cranberry. 90% of those responding were of the opinion that drainage reduces the cloudberry yield in the long term and a full 97% indicated that cranberry crop diminishes as well.

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• Sepponen, E-mail: ps@mm.unknown

The aim of the present study was to increase the knowledge of the anaerobic conditions prevailing in virgin peat soils of different kinds, and on the fluctuation of the aerobic limit. Silver rod method was used to indicate anaerobic conditions and to locate the aerobic limit. The material included 18 peatland sample plots on treeless bogs, in pine bogs and in spruce swamps in Southern Finland. Observations of the discoloration of the silver rods and measurements of ground water level were made from 8 June to 13 August 1968.

The results show that the location of the aerobic limit is dependent of the depth of the ground water table, and usually lies 5–15 cm above the ground water table. Down to 10–20 cm below the aerobic limit, where it reaches maximum, the rate of decomposition of sulfurous organic matter is positively correlated with the distance from the aerobic limit. Deeper it gradually decreases, and in the depth of 25–35 cm no hydrogen sulphide seems to be released.

In the forested peatland types the volume of the growing stock and the increment were dependent on the depth of the aerobic limit only when nutrient content and pH of the peat was more or less constant. Where the aerobic limit was close to the ground surface but the nutrient contents were relatively high, the volume of the growing stock may be comparatively high. Birch (Betula sp.), better than the conifers, is able to stand conditions poor in oxygen. The growing stock was poor in sites where the aerobic limit was near the ground surface, but the nitrogen and phosphorus contents were high, or vice versa. Consequently, aerobic limit is of great importance as an indicator of site quality.

The PDF includes a summary in English.

• Lähde, E-mail: el@mm.unknown

Since Finnish professor A.K. Cajander published his theory on forest types, there have been discussion and contradictory studies on certain forest types. This paper is a litterature review on the thick-moss type in Northern Finland and its parallel types in Kainuu and Southern Finland. First, the principles of Cajander’s theory on forest types is described and discussed. It is concluded that Cajander has described forest site types as their common, genuine variants. Borderline variants have been excluded from the description. 

Second, the North Finnish thick-moss type (Hylocomnium-Myrtillus type, HMT) and its position in Cajander’s system is discussed. Concepts of this forest type have varied considerably, and it has been argued that the type does not fit Cajander’s system very well, as it arises as a result of the invasion of other forest types by Norway spruce (Picea abies (L.) Karst.) with consequent degeneration of the site.  

The writer concludes findings of the results of the previous studies about MHT and its relations to the Myrtillus type. Cajander in his system included the thick-moss type in the moist upland forests as a type whose vegetation is less exacting than that of the Myrtillus type. This position seems to be the right one. Some factors point out the moist nature of HMT: the ability of Norway spruce to compete, a relatively high persipitation, the humidity of the climate in general and the rather poor water percolation capacity of the moraine soil. The HMT sites are relatively poor. It is stated that the opinion that the thick-moss type is secondary state of development of the Myrtillus type has no plant sociological, ecological, mensurational or silvicultural foundation. The type is probably Finland's most dynamic forest type, but in the natural forest its dynamics are confined to such changes as are permitted within the same forest type. HMT must be described as three series of plant association types, which differ from another to some extent. 

The PDF includes a summary in English. 

• Keltikangas, E-mail: vk@mm.unknown

Peatlands amount to more than a third of the land area of Finland. The article includes a review on the peatland complexes and types, their distribution in Finland and how different peatland types suit for draining. Finnish peatlands have typically relatively shallow peat layer, which influences how they suit for agricultural lands or forestry.  Systematic draining of peatlands has been practiced since 1908 in the state forests. In 1908-1919 Metsähallitus (Forest Service) drained slightly over 200,000 hectares of peatlands, and the forest companies are estimated to have drained about similar area. An estimate of how big proportion of the peatlands would be worth draining is deduced, based on existing statistics of the state lands, and on a line survey. In the state lands 35% of the peatlands, about 2 million hectares, are worth draining. If an estimate of the figures of private lands is added, of the total of 5 million hectares of peatlands in Finland about 54% is suitable for draining.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown

The Oulanka National Park is situated in the district of Kuusamo on the eastern border of Finland, close to the Arctic Circle and within the coniferous forest zone. It covers a surface area of 107 km², and is known for the richness of its vegetation and flora, a product of a varied bedrock pattern including occurrences of dolomite. A description is given of the vegetation of the 9 forest and 47 peatland types distinguishable in the area by means of tables based on quadrat surveys. The distribution of each forest and peatland type is described in a vegetation map. The vegetation types are discussed in terms of the structure of their soil and the ecological and floristic features of their plant cover.

The PDF includes a summary in English.

• Söyrinki, E-mail: ns@mm.unknown
• Salmela, E-mail: rs@mm.unknown
• Suvanto, E-mail: js@mm.unknown