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Silva Fennica 1926-1997
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Articles by Pentti Sepponen

Category: Article

article id 5572, category Article
Markku Lehtelä, Juha-Pekka Hotanen, Pentti Sepponen. (1996). Understorey vegetation in fresh and herb-rich upland forests in southwest Lapland. Silva Fennica vol. 30 no. 1 article id 5572. https://doi.org/10.14214/sf.a9217

Fresh and herb-rich upland forest sites in the north-western part of the central boreal vegetation zone in Finland were studied with respect to vegetation structure and vegetation-environment relationships (soil, stand characteristics). Two fresh heath vegetation data sets, one from the northern boreal zone and the other from the central boreal zone, were compared with the data of this study using multivariate methods.

The variation in heath forest vegetation within the climatically uniform area was mainly determined by the fertility of the soil (primarily Ca and Mg) and the stage of stand development. N, P and K content of the humus layer varied little between the vegetation classes. Fertile site types occurred, in general, on coarse-textured soils than infertile site types, may be due to the fact that the sample plots were located in various bedrock and glacial till areas, i.e. to sampling effects.

The place of the vegetational units of the study area in the Finnish forest site type system is discussed. The vegetation of the area has features in common with the northern boreal zone as well as the southern part of the central boreal vegetation zone. The results lend some support to the occurrence of a northern Myrtillus type or at least that intermediate form of fresh and herb-rich mineral soil sites commonly occur in the studied area. It is argued that the older name Dryopteris-Myrtillus type is more suitable than Geranium-Oxalis-Myrtillus type for herb-rich heath sites in the study area.

  • Lehtelä, ORCID ID:E-mail:
  • Hotanen, ORCID ID:E-mail:
  • Sepponen, ORCID ID:E-mail:
article id 5217, category Article
Pentti Sepponen. (1984). Pohjoissuomalaisten metsäammattimiesten käsityksiä metsien ja soiden marjantuotoskyvystä. Silva Fennica vol. 18 no. 3 article id 5217. https://doi.org/10.14214/sf.a15396
English title: Observations of forest specialists in Northern Finland on the berry yield capacity of forests and swamps.

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.

The PDF includes a summary in English.

  • Sepponen, ORCID ID:E-mail:
article id 5172, category Article
Pekka Hynninen, Pentti Sepponen. (1983). Erään suoalueen ojituksen vaikutus purovesien laatuun Kiiminkijoen vesistöalueella, Pohjois-Suomessa. Silva Fennica vol. 17 no. 1 article id 5172. https://doi.org/10.14214/sf.a15087
English title: The effect of drainage on the quality of brook waters in the Kiiminkijoki River basin, Northern Finland.

The present study deals with the effect of forest drainage on some quality factors of brook waters. Under study were several brooks in the basin of the Kiiminkijoki River as well as its main tributary, the Nuorittajoki River. These are located in Northern Finland and belong to the international water program Project Aqua.

The following values were determined for the water samples: pH, electric conductivity, colour, concentration of suspended solids., NO2, NO3, and NH4 nitrogen concentrations, dissolved and total phosphorus, and Ca, Mg, K and Fe concentrations. Water quality in the brooks was monitored prior to and after ditching. A statistically significant change was noted in colour, in the concentration of suspended solids, in the NH4 concentration and in some brooks also in the pH value and in the total phosphorus, K, and Fe concentrations.

The PDF includes a summary in English.

  • Hynninen, ORCID ID:E-mail:
  • Sepponen, ORCID ID:E-mail:
article id 5120, category Article
Pentti Sepponen. (1981). Kivennäismaan raekoon tunnuksista ja niiden käyttökelpoisuudesta eräiden maan ominaisuuksien kuvaamiseen. Silva Fennica vol. 15 no. 2 article id 5120. https://doi.org/10.14214/sf.a15061
English title: Particle size distribution characteristics of mineral soil and their applicability for describing some soil properties.

The particle size distribution affects several properties of the soil, thus, the ability to define the texture type of the soil as accurately as possible in field conditions is essential. The soil particle size classification devised by Atterberg (1912) is used in Finnish forestry. The study is based on a small laboratory material. The correlation between some characteristics of the soil particle size distribution, field capacity and cation exchange capacity were determined.

The particle size characteristics such as the relative proportion of different particle sizes, average particle size (Md) and parameters depicting the degree of sorting were determined. The relative proportion of soil particles below 0.06 mm correlated best with both field capacity and cation exchange capacity. Similarly, the average particle size and the degree of sorting correlated well with the field capacity and the cation exchange capacity.

The use of sorting characteristics is not well-suited to the type of soil sample material containing a high proportion of particles of varying size as was used in this material. Such characteristics are probably more easily applicable to the fine sand and sand sediments which are predominant in Finnish forest soils. The most useful particle size distribution characteristics in soils having a great variation in particle sizes were the average particle size and the relative proportion of silt and clay. Thus, the nutrient and water status of the soil can be predicted to some extent by examining the percentage of silt and clay, average particle size and the degree of sorting.

The PDF includes a summary in English.

  • Sepponen, ORCID ID:E-mail:

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