Acta Forestalia Fennica vol. 16 | 1920

Crown class is useful tool both in forest management and forest mensuration. The study presents a detailed crown classification for Scots pine (Pinus sylvestris L.). It was used to classify the sample trees prior detailed measurements of the crown and stem form. The stem form of a tree was dependent on which canopy layer it belonged. This relation was detected on both Vaccinium and Calluna site type forests. In addition, the stem tapers faster in poorer forest site types compared to better sites. The shorter the self-pruned part of the stem is, the faster the stem tapers. According to the study, the stems of stunted trees taper faster than trees of other crown classes. Also the age group affects stem form.

The PDF includes a summary in German.

• Lakari, E-mail: ol@mm.unknown

No agreement has yet been reached about formation of podzols, and their distribution in Finland has not been studied. It is, however, known that most of the forest soils are leached. The compacted ortstein is relatively rare in Southern Finland, but common in the gravely soils in Lapland. This study focuses on whether ortstein formations facilitate paludification. The study is based on observations in drained peatlands in Toivakka and Multia. Ortstein can rarely be found under the actual peatlands. It is often formed in mineral soil threshold areas, where it can be up to one meter thick. The ortstein formation was stronger in poorer soil types. Also, it is compacted into a harder layer in gravely soils than in sandy soil. These formations seem to be caused by humus-rich water flowing from the peatlands.

The soil is not leached, and ortstein is not formed in wet, low-lying peatlands, and has, therefore, no role in their paludification. In drier peatlands, especially in slopes, an A horizon can be found. However, ortstein seems not to have a marked effect on paludification. When ortstein is formed in mineral soil threshold areas, their formation seems to be caused by water flow from the peatland. It may make the threshold area more compact, and thus further facilitate paludification.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@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 aim of the study is to find out how do the peatlands develop after drainage and how does the type of peat affect the growing conditions of the forest on it. Study is based on measurements made in summer 1919 in about middle Finland (districts of Loppi, Yläne, Kihniö, Nerkoo, Orivesi, Vilppula, Multia and Karstula). The macroscopic identified content of the peat was analyzed: the different peat types were categorized according the species of the most abundant plant remains. The characteristics of the studied peat types are represented.

The conclusion of the study is that when deciding about the suitability of the drained peatland for afforestation, the thickness and content of the peat must be considered in addition to peat type.   

• Lukkala, E-mail: ol@mm.unknown

In South-West Finland the usual method to make leaf fodder for cattle has been to cut the branches and collect the new sprouts again next year. According to this review, the most common tree species to be topped is Betula sp. Downy Birch (Betula pubescens Ehrh.) grows shoots easier than silver birch (B. pendula Roth). The topped forests are usually small and situated near the settlements, next to the fields and meadows. The birch trees are typically cut when they are 15-20 years old. Regularly topped birch rots easily and seldom exceeds 50 years. The capacity to grow shoots depends on the age of the tree, site and time of the cutting. The risk for rotting can be decreased by removing only part of the shoots and cutting the shoots a short distance from the base of the shoot. Collecting leaf fodder decreased in Finland, and was common only in the South-West Finland and Åland.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@mm.unknown

The investigations that have studied peat layers in peatlands have shown that the peatlands in several countries have layers containing tree stumps of different tree species. The stump layers have been explained by local hydrological changes that have caused paludification, or changes in climate.

Peat layers were studied in drained peatlands in Finland, and ditches were used to study the peat profiles. A peatland in Multia in Central Finland was studied in more detail. Tree stump layer patterns that would support the climate change explanation was not found in the Finnish peatlands. The peat changes usually gradually more oligotrophic towards the surface. The stump layers seemed to be caused by local drier periods. According to the layers of Sphagnum-peat near the bottom of the peatlands and the pollen studies indicate that the peatlands have been formed at different times. In South-West Finland, the peat profiles had more apparent layer patterns than in Central Finland, but these were not considered to be caused by changes in climate.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@mm.unknown