Articles by O. J. Lukkala

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation discusses forest management practices of drained peatlands and the allocation of responsibilities in draining of peatlands between district forest officers and forest officers responsible of drainage work. Problems has occured in those cases, when the process of draining had lasted so long that at the time of final assessment of the project the first ditches have already needed maintenance.

• Lukkala, E-mail: ol@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes afforestation of drained peatlands. 

• Lukkala, E-mail: ol@mm.unknown

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes different kinds of peatlands and their suitability to draining and forestry.

• Lukkala, E-mail: ol@mm.unknown

The tree canopy adsorbs part of the rainfall falling on a forest, therefore only part of it reaches the soil. This report presents results concerning interception of precipitation and groundwater level in forests of varying canopy cover. The study belongs to a larger survey on afforestation of drained treeless bogs. The rainfall was measured daily in the open fields and in the adjacent forests. The forests, mainly Norway spruce (Picea abies (L.) Karst.) dominated, were divided by the canopy cover into five classes from over dense to sparsely stocked.

The results show that in a dense, tall Norway spruce stand, light rainfall can almost entirely be adsorbed by the canopy. The heavier the rainfall, the larger proportion of it reaches the ground. Only 30% of a 5 mm rainfall reaches the ground, while 80% of a 20 mm rainfall reaches the ground. Interception of precipitation decreases gradually when the density of the forest decreases. Canopy of Scots pine (Pinus sylvestris L.) and birch (Betula sp.) stands of corresponding density adsorb less rainfall than Norway spruce canopy. Groundwater level was higher in treeless areas than in areas covered with forest. Widescale clear cuttings should, therefore, be considered carefully in forest areas that are prone to become peaty.

• Lukkala, E-mail: ol@mm.unknown

Pollen analysis has given information on development of the tree species composition after the ice age, but this kind of studies have not been published in Finland. In this study, pollen analysis was performed in five peatlands in the southwest Finland. According to the analysis, the forests of the area have had similar tree species composition for many thousands of years. Scots pine (Pinus sylvestris L.) has been the dominant species as long as there has been Norway spruce (Picea abies (L.) H. Karst.) in the area. Norway spruce seems to have arrived about 4,500 years ago. It increased slowly in the beginning, and after reaching a maximum has been slowly decreasing. Before spruce arrived, Betula sp. was more abundant, and seemed to be the dominant tree species in some places. Traces of fire in the peat layers indicate that forest fires have been common before people arrived in the area, and may have beneficial to birch. Like Betula sp., also Alnus sp. were more common before spruce arrived. Also pollen of other broadleaved species, for example, Tilia sp., Ulmus sp. and Corylus could be found. However, Quercus pollen was not found. The paludification of the peatlands had begun at different times which indicates that there has not been a common cause for the development of the peatlands in the area.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@mm.unknown

The type of the peatland and its classification as forest site (height-over-age-classification) are important information when the drainage potential of a peatland is defined. The gradient and thickness of peat bed are also significant.

The observations for the study have been collected in state owned forests in middle-Finland. The thickness and gradient variations have no clear differences between different types of peatlands. The results show that from the view of drainage for afforestation, the peatlands that are good or suitable for afforestation are flatter and more even that those less suitable. The more suitable peatlands also have thinner peat bed and bigger gradient.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Lukkala, 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

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

The article presents a survey on distribution of fertile lands, soil types and site classes in Savo and Karelia in the central and eastern parts of Finland. The survey was based both in existing publications and statistics, a line survey, and visual observations during field trips. The site quality classification is based on the vegetation and occurrence of indicator plant species. The article lists distribution of indicator species in different forest site types on maps of the area. In addition, a review of history of land use and agriculture give indications of the location of the fertile lands in the area. A map of the forest site types in different parts of the area illustrate the data collected from the different sources.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@mm.unknown