Articles containing the keyword 'suotyyppi'

The possibilities of using a pot method to determine the need for fertilizer application were studied. Seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) were grown in peat samples that had cylindrical shape with a diameter of 25 cm and height of 35 cm. The samples represented three different peatland types, and were fertilized with two levels of phosphorus, potash and nitrogen. Two transplants were planted per pot. The development of the seedlings was followed for three years.

Phosphorus seemed to be of greatest importance for the growth of the seedlings, but nitrogen was also required in the poorest peatland type. Potash did not give statistically significant results. NPK application gave the best response. The usability of the method was studied by following the development of the roots. It seemed that the diameter of the pots was too small and restricted the growth of the root systems.

The PDF includes a summary in English.

• Erjala, E-mail: pe@mm.unknown
• Saramäki, E-mail: js@mm.unknown

There are about 155,000 ha of fen-like pine swamps (eutrophic pine bogs) in Finland, major part of which are situated in Northern Finland. In the classification system for drainability of peatlands, this type of peatlands had been placed in the first class. The study presents a new evaluation for the peatland type, based on vegetation and tree growth.

According to a previous study, the vegetation of fen-like pine swamps can be characterised by distinctive plant communities that seem to reflect the fertility and high pH of the underlying soil. In this study, the fen-like pine swamps were divided in two subtypes based on the vegetation: proper fen-like pine swamps and fen-like pine swamps with ericaceous shrubs. Both have distinctive vegetation, which is described in the article. The distribution of the subtypes seems to be different: fen-like pine swamps with ericaceous shrubs are more common in eastern parts of Northern Finland. The two subtypes could be divided in different drainability classes according to tree growth, proper fen-like pine swamps belonging to class 1 and fen-like pine swamps with ericaceous shrubs to class 4.

The article includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

The aim of the study was to develop an determination method to define vegetation type of fen-like pine swamps, which are combinations of two peatland types, quagmire and pine swamp. Typical for this peatland type is that the vegetation is very heterogenous. Patches of different types of plant communities are found within a small area, but in a large scale, there are only few main types of plant communities. The commonly used way to use sample plots to study tree stands suit poorly to determine the type of this kind of heterogenous ground vegetation. The article compares strip survey and circular plot survey, of which circular plot survey is determined to be less time consuming. The article describes a way to choose the locations of sample points to achieve most correct areas for different plant communities.

The article includes an abstract in German.

• Heikurainen, E-mail: lh@mm.unknown

According to studies following the development of vegetation of drained peatlands, it seems that they have transformed to a relatively stable plant communities during the succession. In earlier studies it was assumed that after drainage a mire type would develop to a corresponding forest site. This investigation studies what kinds of plant communities are formed during succession of different mire types on peatlands drained for forestry in the southern half of Finland. Understorey vegetation was studied in 18 sample plots established by Forest Research Institute on drained peatlands. In addition, sample plots were studied on peatlands in natural state.

The results suggest that understorey vegetation on peatlands drained for forestry have developed into plant communities, the most advanced of which are the so-called dry plant communities. They represent transformed site types, which are the following: drained peatlands with upland herb-rich vegetation, drained peatlands with upland grass-herb vegetation, drained peatlands with upland Myrtillus site type vegetation, drained peatlands with upland Vaccinium site type vegetation, and drained peatlands with upland Calluna site type vegetation. Drained peatlands with upland Cladonia site type vegetation seem to be a temporary type caused by incomplete drainage. The transition between Myrtillus and Vaccinium dominated dry plant communities is not clear, but especially the pure Vaccinium vitis-ideae communities justify its place as an independent plant community. The dry drwarf shrub plant communities are also stable.

The PDF includes a summary in German.

• Sarasto, E-mail: js@mm.unknown

According to the theory of peatland types, particular peatland types, after sufficient drainage, change into certain forest types. It has been found, that the range of forest types in peatlands in different stages of draining is as large as on mineral soil; and comprise Cladina, Calluna, Vaccinium, Myrtillus Oxalis-myrtillus and grove types. Poor peatland types change into poor forest types, better for better types. However, a Swedish scientist Mellin suggested that after effective drainage especially oligotrophic bogs, when well drained, change usually into Myrtillus type.

The different conclusions are due to the fact that the same bog type may develop into different forest types according to the effectiveness and duration of the drainage. Greater the decay of the peat bog layer, the more exacting is the type of vegetation which appears. Bog types of classes V, IV and III (Finnish classification of site quality) change into a Myrtillus type, as do the poorer peatland types of class II. The types vary, however, in their economical drainage value. The fact that bogs which in their natural stage are clearly different in their site quality change after through drainage into the same forest type, is explained by the chemical quality of the peat. However, class I and the best types of class II bogs change into better forest types because they as eutropchic bogs are richer in nitrogen and lime. This difference persists despite of effective draining.

It has been shown that the development of eutrophic peatland types at the forest type stage also differs clearly from the development of oligotrophic peatland types. The Finnish classification of drainage value shows correctly the relative drainability when using normal spacing of ditches. The notes on forest types on mineral soil should, however, be replaced by corresponding notes on the transitive types between bog and forest types.

The PDF includes a summary in Swedish and English.

• Keltikangas, E-mail: vk@mm.unknown

The relation between the occurrence of forest site types and swamp types was studied using data collected in the national line survey of Finnish forests carried out in 1921‒1924. The majority of peatlands in Finland has been formed by forest land becoming paludificated. When the peat layer is thin, the fertility of the peatland depends on the underlying mineral soil, consequently, good swamp types occur on fertile subsoil and poor types on poor subsoil. When the peat layer becomes thicker, the relationship weakens. The surrounding mineral soils influence the quality of the peatland by the runoff from the catchment area. The direct comparison of forest site and swamp types is not possible, because for one forest site type there are several swamp types that have different levels of humidity. According to the study, a very distinct mutual relation can be seen between occurrence of forest site types and swamp types.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@mm.unknown

The vegetation of the forest and peatland site types in Northern Finland differ markedly from those in Southern Finland, also the vegetation of the subtypes in the north is distinctive. A line survey was conducted to study the distribution of forest and peatland site subtypes in Northern Finland.

The vegetation of rich grass-herb forest types differs little from the poorer grass-herb forest types in Northern Finland. They abundance decrease towards north. The main fresh mineral soil sites are Myrtillus site type, Hylocomnium-Myrtillus site type and their paludified forms. The abundance of the fresh mineral soil sites decreased towards north so that in Kemi the proportion was 20.5 and in Lapland 12.0%. A transition from the fresh to the drier site types is gradual. The Vaccinium site type that is dominant in the south, is rare in the north, where it is replaced by Empetrum-Vaccinium type. The proportion of dry forest sites increase towards north, in average their distribution is 25% of the lands. There are numerous subtypes, which can be merged in to four main site types: Calluna, Cladina-Calluna, Myrtillus-Cladina and Cladina site type. The peatlands are more abundant in the southern part of the study area. The most common peatland types are pine swamps.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown

• Kujala, E-mail: vk@mm.unknown

The aim of the study was to determine how the spacing of drains affects the economic results of forest drainage projects. On the basis of empirical material consisting of 411 sample plots, it is presented marginal cost curves showing how many meters more of drains it is needed to increase the value of stock, 35 years after the drainage, by a value equivalent of one cu.m of coniferous pulpwood. Results indicate that wider spacings ought to be used on poor sites, on sloping swamps, and in the north.

The PDF includes a summary in English.

• Keltikangas, E-mail: mk@mm.unknown