Articles by Matti Leikola
Category : Article
This article is a book review on a German book ’Die Fichte’ by H. Schmidt-Vogt, summarizing the knowledge of the genus Picea and its 36 species.
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Leikola,
E-mail:
ml@mm.unknown
This article is a book review on a book ‘The problems of Forest-based Development as Illustrated by the Development Discussion’ by Jussi Raumolin, concentrating on the development of forestry.
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Leikola,
E-mail:
ml@mm.unknown
On 23th of March 1989 professor emeritus Paavo Yli-Vakkuri celebrated his 75th birthday. In 1963–1977 he acted as professor of silviculture and Head of the Department of Silviculture at the University of Helsinki. Due to his personality and positive attitude towards students and younger colleqaues, silviculture became the most popular subject for the graduate and postgraduate forestry students, and active research flourished at the Department of Silviculture during his era. This issue of Silva Fennica is dedicated to Paavo Yli-Vakkuri in gratitude and respect for his professional accomplishments in academic studies and research in forest sciences.
The PDF includes an abstract in English.
This paper is a commentary which summarises the history of the Finnish Society of Forest Science and its connection to the corresponding society in the field of agriculture, the Scientific Agricultural Society of Finland. The original idea when the Scientific Agricultural Society of Finland was founded was that the society would function as a scientific society for both forest scientists and agronomists. However, A.K. Cajander founded a separate academy for forest sciences. The article discusses the implications of this decision.
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Leikola,
E-mail:
ml@mm.unknown
A method for calculation of the effect of practical fertilization for economic evaluation is presented and discussed. 55 Norway spruce (Picea abies (L.) H. Karst.) dominated stands on Oxalis-Myrtillus type sites were surveyed five to eight years after fertilization with nitrogen (90-170 kg/ha). The relationships between the fertilization effect and various stand characteristics were discussed. Fertilization increased the growth of the stands on an average by 2.2 m3/ha/year. In total the increase of tree growth during the research period was 17.5 m3/ha. This corresponds to a yield of 525–659 FIM/ha.
The PDF includes a summary in English.
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Westman,
E-mail:
cw@mm.unknown
- Leikola, E-mail: ml@mm.unknown
- Nummi, E-mail: tn@mm.unknown
1983 was the so-called ”Year o the Forest” in Finland. To mark the occasion, the Society of Forestry in Finland (now the Finnish Society of Forest Science) arranged a series of Studia Forestalia lectures which covered, in general form, a wide range of subjects. 12 of the 14 lectures given in this series are included in this edition.
The PDF includes a summary in English.
The purpose of this study was to examine the use or citations in Finnish forestry publications using source analysis. The material consisted of three of the four main series published in the field of forestry in Finland. The study was confined to three sample years in the middle of each decade during the period of 1910–1980.
The use of references in Finnish forestry sciences was abundant: from 30 to 60 references per report and from 1.1 to 1.7 references per page. The amount of self-citations varied from 6 to 9%. The half-time of the references was, in general, very long varying from 8–12 years in forest economics to 14–17 years in silviculture and forest biology. The amount of ”classical” publications was 4–11%. The amount to Finnish references was large varying from 30 to 59%. Anglo-Saxon series made 22–24%, Scandinavian 11–13%, German 7–9%, Russian 1–3% and French series less than one per cent of all references.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
This article is a book review on a Finnish book 'Dynaamiset mallit kasviekologiassa' by Holmberg. A., Mäkelä A and Sievänen R., concentrating on dynamic models in plant ecology.
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Leikola,
E-mail:
ml@mm.unknown
This article is a book review on a Finnish book 'Luonnon olosuhteiden huomioonottaminen uusien asuntoalueiden suunnittelussa' by Kellomäki, Seppo and Lakka, Aura, concentrating on utilization of forests in urban planning.
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Leikola,
E-mail:
ml@mm.unknown
MAB Project 2 concentrates on the influences of man’s activities on forests with no special consideration to any particular research field. At the same time as the swift development of research methods has brought the natural sciences and forest biology very near to each other, the circle of users of research results in forest biology has widened to include area and city planners etc. In Finland, the main role of MAB Project 2 is to promote mutual exchange between the users and producers of research results in forest biology and to facilitate both national and international co-operation between all research workers and organizations interested in this field.
This paper was presented in the ‘Man and the Biosphere’ programme project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki.
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Leikola,
E-mail:
ml@mm.unknown
The part played by research work in guiding the management and utilization of Lapland’s forests is examined in this publication. The review has been written to mark the 70th anniversary of the Finnish Forestry Society (now the Finnish Society of Forest Science).
The climate in Lapland is very severe and, owing to the lack of experience abroad, forestry has been forced to follow the guidelines set by domestic research activity in Finland. Research work was very active in Lapland the 1910’s, 1920’s and 1950’s, and the main outlines for forestry utilisation were soon established. In the 1950’s, there was a strong trend prevailing to develop forestry, with the result that a change took place in favour of clear-cutting. The cool climate period in the 1960’s caused considerable damage to young plantations. In order to find means to rectifying the situation and to devise new guidelines for forest management, The Finnish Forest Research Institute established a number of research stations in Lapland.
Research activity has had a pronounced effect on the management and utilization of forests in Lapland. Present-day problems have been caused more by the international situation than by difficulties in the management of forests in Lapland.
The PDF includes a summary in English.
The article describes the series of events and the decisions which in the years 1908–1911 resulted in transfer of the field courses in silviculture of the University of Helsinki from the old training region of the Evo Forest Institute in Central Finland, where higher education in forestry had been given since 1860. The establishment of the new training region of Siikakangas and the building of the new Forest Training Station Hyytiälä in 1911–1912 are also described, as well as the arguments behind these decisions and the motives of the forestry faculty of the University of Helsinki.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
In the article some aspects concerning the measurement of environmental factors are discussed. Special attention is given to the following questions: The correct way of determining the active surface in a forest ecosystem, the time factor in measurement processes, and the mutual correlative relationships between the environmental factors. Analysis of the data is also taken into consideration.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
The purpose of the study was to measure the throughfall in a managed Scots pine (Pinus sylvestris L.) stand in Southern Finland (61°47’, 24°18’). Totally 20 summer rain gauges (collecting area 100 cm2) were placed randomly in form of a lattice of 100 squares, each 2x2 m. Six rain throughs, 15 cm x 150 cm, were placed in the experimental stand. Auxiliary precipitation measurement was done in an opening, by using four summer rain gauges, two rain throughs and one recording rain gauge. The throughfall was followed in May–September 1967.
In comparison with summer rain gauges, the rain throughs gave too low values when the precipitation was below 3 mm/rain shower. Accordingly, only the results of rain gauges were used. The rate of throughfall was determined by the amount of precipitation and the rate of heaviness of the rain shower. When trying to describe the relative amount of throughfall by using various characteristics of the stand, the equitation proposed by Seppänen (1964) proved the best. When the rate of throughfall was depicted with the distance between the summer gauge and the nearest tree, there was negative correlation between these. The correlation was negative under heavy rains, but positive in small rains.
Various factors of uncertainty are discussed. During long periods the areas under Scots pine canopies reach more rain water than those between the canopies, which may be important when analysing the spatial distribution of ground vegetation.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
This article is a book review of a book ’Fundamentals of forest biogeocoenology’ by V. Sukatšev.
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Leikola,
E-mail:
ml@mm.unknown
The purpose of the present study is to throw light on the termination of diameter growth of Scots pine (Pinus sylvestris L.) in old age in northernmost Finnish Lapland. The material consists of thirty over-mature, dying or already dead standing trees grown in natural state. In 1907 the stand was marked for cutting, but the harvest was never carried through. Now the old labels served as a means for cross-dating the year of the final termination of growth.
It was found that as pine becomes senile its annual ring formation becomes incomplete. At first diameter growth stops in the middle part of the stem, then at the butt end, and at last on the canopy level. No correlation between the mean temperature of July and the dying of the tree was found. The average age for dying for the pine in the stand was 420–450 years. After the tree has died it takes about 35–40 years before it has become a silvery, branchless dead bole.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
The objective of this investigation was to study the influence of stand density of white birch (Betula pubescens Ehrl.) on the minimum temperatures in the stand during the growing season, and the actual minimum temperatures of the leading shoot of Norway spruce (Picea abies (L.) H. Karst.) seedlings growing in the open. The 40-year-old uniform white birch stand was situated in 142 m above the sea level in Southern Finland. The stand was treated with thinnings of three different densities in 1961.
Air temperature was recorded in four sample plots at heights of 0.1 m, 0.5 m, 1.0 m, 2 m and 4 m. In the stand of moderate density, temperatures were measured at heights of 6.0 m, and in the stand of full density at 6.0 m, 8.0 m and 10.0 m.
The temperature differences between stands of various densities proved to be rather small. Especially the thinnest stand differed very little from the open area. The soil surface has in all cases been warm compared with the higher air layers indicating meadow-fog-type by Geier (1965). On cloudy or windy weather all the temperature profiles in the various stands resembled each other. The difference between the air temperature and temperature of the spruce shoot was greatest at midnight and decreased steadily thereafter.
The problem in using shelter stands for spruce regeneration areas is that optimum shelter stand density is difficult to define. Already a thin shelter stand causes drawbacks to the young seedlings, but in order to be effective enough against early frosts, the shelter stand should be comparatively dense.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
- Pylkkö, E-mail: pp@mm.unknown
An explorative study on wind conditions in a well-managed Scots pine (Pinus sylvestris L.) stand was made in Southern Finland. The wind velocity was recorded continually with two cup anomometers from April to August, 1964. The two levels used were 2 m and 9 m. The wind velocity was lower at 2 m than within the canopy at 9 m. The dependence on the absolute wind velocity at 9 metres was logarithmic. The wind velocity did affect the difference between daily minimum temperatures at the two levels; the difference in the maximum temperatures was affected only in May and August.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
Category : Article
The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.
The standing volume prior to the shelterwood cutting was on average 236 m3/ha (ranging from 80 to 428 m3/ha) and after the cutting 120 m3/ha (39–220 m3/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.
The PDF includes a summary in English.
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Leinonen,
E-mail:
kl@mm.unknown
- Leikola, E-mail: ml@mm.unknown
- Peltonen, E-mail: ap@mm.unknown
- Räsänen, E-mail: pr@mm.unknown
The study analyses Finnish academic dissertations in forestry sciences on the basis of number published and yearly trends, length, topic, sources of funding and guidance, and the doctoral candidates’ background and career development before and after disputation.
From 1912–1984, 131 dissertations in forest sciences were published. The majority of them were written in Finnish. The length averaged 151 pages. In general, the more rapidly the dissertation was prepared, the better grade it received.
The majority of doctors in forest sciences come from well-to-do families, in cities located in Southern Finland. They constitute 2–6% of the total number of graduating foresters. At the time of disputation their average age has been 36 years. Doctors have used job changes to improve their position in the hierarchy of their employing institutions.
The PDF includes a summary in English.
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Leikola,
E-mail:
ml@mm.unknown
This study examines the extent, structure and development of the publishing activity of Finnish forest sciences between 1909–1978. The subject comprises the four main forestry series; Acta Forestalia Fennica, Silva Fennica, Communicationes Forestales Fenniae and Folia Forestalia. Collectively, 532 authors produced 1,715 publications containing 90,134 pages.
The total number of pages of forest science publications doubled every 25 years. Only a small number of short research reports (few pages) and long monographs (over 200 pages) were published. The median age class of the authors was 36–40 years. The so called Lotka’s law, which describes the productivity of the researchers, proved to be valid in forest sciences. According to this law, among other things, one tenth of the researchers produced approximately half of all publications. Despite changes, the structure of the publisher community remained roughly constant. Every year approximately 30% of the author community was composed of new members, whilst 19–26% of authors stopped publishing.
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Leikola,
E-mail:
ml@mm.unknown
The influence of various environmental factors on the diameter growth of trees has been studied based on data collected by following daily increment of trees and various environmental factors during the growing season in 1964–1967. The field work was carried out in two experimental stands, a Scots pine (Pinus sylvestris L.) stand and a mixed stands growing birch (Betula sp.), Norway spruce (Picea abies (L.) H. Karst.) and Scots pine, in Southern Finland.
The results show that the temperature sums preceding the beginning of diameter growth were of the same magnitude in the years studied, which indicates dependence in the relationship. Formation of new xylem cells took place in the pine stem ca. every third day when the diameter growth was most active. No summer growth inhibition was detected in diameter growth.
None of the cumulative temperature sums tried determined the time of cessation of diameter growth. In several cases, positive correlation was found between the length of the growing season and the width of the annual ring formed. When studying the relationships between the diameter increment and the environmental factors, it was found that diameter increment was totally masked in the records by the hydrostatic changes in the stem. Relationships between the diameter increment and the environmental factors of the second day preceding growth were found to be poor. In studying the deviations of the recorded daily increments from the regression surface, no clear general trend was seen for pine and spruce, but clear diminishing trend toward the end og the growing season could be seen for birch in 1967.
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Leikola,
E-mail:
ml@mm.unknown
