Acta Forestalia Fennica vol. 34 | 1929

The volume 34 of Acta Forestalia Fennica is dedicated to professor Dr. Aimo Kaarlo Cajander, who celebrated his 50^th birthday in 1929. The article is an introduction to his work and career. He has been responsible for developing the education in forestry, and planning and developing of forest research in Finland.

The PDF includes the text in Finnish, Swedish, English, German and French.

• Finnish Society of Forest Science, E-mail: info@metsatiede.org

In practical forestry being able to divide the stem into timber assortments in the best possible way is very important.  Defining the decrease in diameter of the stem plays an important role in that. The article aims to define the slenderness as the relation of the tree height to its breast height diameter. The decrease in diameter is taken into account by measurements of diameter above the breast height. The study is based on the measurements conducted in 1924 for the inventory of forest resources of Finland.

The influence of the stand density to the relationship between height of the pine and the breast height diameter is smaller in the more fertile sites than in the less fertile sites. In the more dense stands are pines more slender than in the sparser stand on all forest types.  

• Lappi-Seppälä, E-mail: ml@mm.unknown

The article gives a summary of the range of the wood-technological research, and suggests that the research in the subject in Finland should be divided in two parts: research on problems of wood-technology in the strict sense of the word, and those concerning wood refinement and the problems of wood technology, related to the latter. The wood-technology research would be addressed to the Forest Research Institute, and the research on wood refinement to the organization to be founded by the wood manufacturing industry. Finally, main subjects to be studied are listed.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

• Lassila, E-mail: il@mm.unknown

The article summarizes the observations about forest types from different parts of Estonia. The chosen examples represent the normal forest where age class division is natural and the species composition has not been altered through felling or grazing. These are mainly found in the areas of earlier manors of the nobility. The samples are only from mineral soils. Vegetation analysis and middle-European height-over-age-survey were made.

Because of the great share of herb-rich-forest the forest type classification for Estonia is complex. There are many types that have not been described earlier.

The study describes the characteristics and the vegetation types of the heath forests, fresh forests, half-herb-rich-forests and herb-rich-forests.        

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

• Linkola, E-mail: kl@mm.unknown

The article includes observations on forest site types in Canada and the United States, with special emphasis on forests of lodgepole pine (Pinus murrayana, now Pinus contorta Douglas ex Loudon) which the author considers a species that can become a favourite exotic tree species in Finland. Some notes are made also about Jack pine (Pinus banksiana Lamb.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. The author was not able to make a systematic forest type investigation, because the journey was made on another purpose. The article describes the vegetation and climate of the visited areas, and divides the forest site types in three groups: Dry forest site types, moist forest site types and grass-herb site types. The vegetation and plant species on several subtypes are described in detail.

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

• Ilvessalo, E-mail: yi@mm.unknown

Doctor Lauri Ilvessalo modified tree classification developed by professor Gunnar Schotte to develop a tree classification and thinning system that suited Finnish conditions. His system was first applied when the Finnish Forest Research Institute began thinning experiments in a large scale in 1924. The system distinguishes four crown storeys: the predominating crown storey, dominated crown storey, emergent trees and undergrowth. Into the predominating storeys belong dominant trees and co-dominant trees, and into the dominated storeys the intermediate and ground trees. The trees in all the storeys can be divided in to normal trees with well-formed crown and stem, trees with defectively developed crown, trees with defective stem, and injured and diseased trees. The article describes different thinning methods (cleaning thinning, selective thinning from below, selective thinning from above, increment felling, freeing felling) using the tree-classification.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

• Ilvessalo, E-mail: li@mm.unknown

Man’s existence on the earth depends on his ability to make use of the space, time, material and energy provided for him by Nature. The more able a nation is to increase the utilization of these resources, the higher is the culture and the standard of life in the nation.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

• Jutila, E-mail: kj@mm.unknown

There are several competing theories about forestry: school on continuous forest management system, school on profitability of forestry and a dynamic view on economics. The article discusses the pros and cons of the different theories or viewpoints and wider the essence of forest as an economic asset.

To serve the needs of the practical forestry and the economics related to forests the forestry needs to seek for standardization in relation to growth potential of the forests and market orientation of the timber. A modern theory of forestry needs to base itself on both.  

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

• Hagfors, E-mail: eh@mm.unknown

In 1926 the state of Finland payed taxes to the local municipalities from a half of the net returns the state forest and state owned wood manufacturing industry produced. The taxes payed by the forest administration to the municipalities totaled 4.75 million Finnish marks. The state forests are located mostly in Northern Finland, thus the relative amount of municipalities that get taxes from the state forestry were higher in the north. The municipalities that benefited most from the tax revenues from the state were Savukoski, Pudasjärvi, Suojärvi, Rovaniemi, Taivalkoski, Kuhmoniemi, Turtola, Pielisjärvi, Ilomantsi, Korpiselkä and Suistamo. About half of the municipalities (264) got tax revenues from state forestry. However, if this tax revenue was removed, it would raise local tax rate in relatively few municipalities. it has been proposed that state should pay taxes from the state forests on the same principles as the private forests. To move to area based taxation in the state forests would, however, increase the taxation of the state five-fold. The taxes from the state forests are not appropriate way to support the poorest municipalities. Better suited would be, for instance, state subsidies. Therefore, the taxes payed from the state forestry to municipalities should be abandoned.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

• Lakari, E-mail: ol@mm.unknown

The article discusses the adaptation mechanisms of the trees against storms or stormy winds. Two main aspects are revealed: the adjustments of stem and crone and the adjustments of the root system.

The shorter the stem the lower the danger of windfall or windbreak. The wind load of a tree depends on where it is situated; on the open field the wind is much stronger than in closed stand. The tree adjusts its height on the situation: where the wind load is high the trees remain smaller. A tree adjusts its crone also depending on the wind. The branches of spruce are relatively thin and very flexible. An alone standing trees have a flat or umbrella-like crone. Trees with a deep-going main root (tap root) are best protected against windfalls. When there is no tap root, the horizontal roots need to strengthen to offer the needed support.

The protection from windfalls is an important question in the practical forestry. Knowing the factors affecting the wind tolerance of a tree the forest management can be planned to support them.  

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

• Laitakari, E-mail: el@mm.unknown

The article discusses the different methods to classify forest sites and applies the methods to classify forests in Latvia. The three methods are: height-over-age classification, from standpoint of floristic (botanical- plant geographical standpoint), and forest types. A good classification method must: describe the main characters of a site illustratively, the classification units need to relate to each other, and the classification method is easy to use in practice. In contrast to other methods, by forest type classification the stand and the site are considered as whole and hence it is considered as the best of the three.

There is one classification system for the whole Latvia. The forests can be divided into permanent and transition types. In the permanent types the site factors stay rather unchanged and the site characters tally with the requirements of the dominant species. sites where the current tree species produces less than optimum growth are classified as transition types.

The forest types have changed over the time because of leaching of the nutrients from the soil.   

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

• Kirstein, E-mail: kk@mm.unknown

In a natural state growing closed forest the amount of timber grows yearly. However, in the same time the timber volume also decreases when part of the trees die in the competition for light and other growth factors.

There are many interactive functions and characteristic that influence the growth and drain in a stand. These can be illustrated as mathematical models. The article discusses a set of models.

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

• Lönnroth, E-mail: el@mm.unknown

The economy of the forestry in private farms in Southern Finland was studied based on the statistics compiled by the Board of Agriculture, and published in the series Tutkimuksia Suomen maatalouden kannattavaisuudesta (Investigations into the profitability of agriculture in Finland). The results present income, expenditure, assets, gross return, net return of the forests in the farms in 1924‒1926. The annual net return of the smallest farms (<10 ha forest land) was 884 Finnish marks and in the largest (>100 ha forest land) 48,335 Finnish marks. The location of the farm influences greatly the net return. For instance, the transport costs of timber from the forest is higher in the larger farms. To utilize the advantages of management of a large forest area requires knowledge about forestry. In addition, the fellings were higher in the small farms during the period. The net return is greater in the private forests than in the state forests located in the same region. Agriculture gave the farms larger net return than the forestry.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

• Saari, E-mail: es@mm.unknown

The article presents forests on Tehri Garhwal district (former kingdom, now part of India). Most of the area is middle-mountainous area with valleys and hills. The forests in the area belong to three different forest zones: tropical, temperate and alpine. The article presents the characteristics of the forests and vegetation for every zone. 

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

• Heske, E-mail: fh@mm.unknown

The article presents the observations made on peatland “Savonneva” in summer 1929 in commune Pulkkila, north-west Finland. The study concentrates on the relationship between groundwater level and growth of trees. The areas was first ditched in 1894, when a main ditch and a side ditch were dug. The ditches were repaired several times, last time a year before the study took place.    

Parts of the area has been taken for agricultural purposes, and other areas have been naturally afforested. The size and abundance of trees varies strongly because the drainage of the area has been uneven. Closer to the main ditch the forest grows better than further away. There is a clear line between the afforested and open areas.

It seems that the tree growth decreases faster with certain groundwater levels than if the groundwater level is deeper.  

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

• Kokkonen, E-mail: pk@mm.unknown

After critically reviewing earlier studies on soil properties and their influence on forest growth and yield, it seems that defining the forest yield could be possible by means of soil properties. To be able to do so, the site needs to be defined and delineated in some other way. It is also necessary to decide the right soil properties to study for the purpose.

For the classification of forest sites the results of soil analyses need to be compared with growth and yield data from the site. To further the practice of classification of forest sites by means of soil studies, four aspects need to be taken into account:

1)  the site needs to be delineated beforehand according its vegetation, preferable with Cajander’s forest type classification

2) the experiments about soil needs to be done for as many properties as possible

3) the studied sites need to be as representative as possible in their class

4) there are as many samples for one site as possible studied

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

• Aaltonen, E-mail: va@mm.unknown

The aim of the study was to determine the value of common alder (Alnus glutinosa (L.) Gaertn.) in forestry by studying an unusually large alder forest in Kontusaari, an island of the size of 75 hectares in the Southern Finland. The forest is grass-herb forest site type. The coastline of the island is partly flooded. Wood has been harvested mainly for fuel wood. The stands have regenerated easily from stump shoots. The annual volume growth is slightly higher than what would be in Norway spruce (Picae abies (L.) Karst.) or Betula sp. stands, estimated based on growth and yield tables made by Ilvessalo. The site is well suited for common alder, and it is difficult to judge what the yield would be for other species on the site.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

• Hildén, E-mail: nh@mm.unknown

The article is a review on the history of forestry in Pekkala estate, a private woodland estate in Ruovesi in Southern Finland. The estate had 7,300 hectares of land in 1929, of which 500 hectares were agricultural lands. It was owned by the Aminoff family since 1822.

The household wood harvesting of the tenants was considered a problem until the farms of the tenants (crofters) became independent in 1921, when the farms of the tenants were parceled out from the main estate. The shifting cultivation of tenants was banned already in 1824. Demand of wood was low until 1870s. in 1865 the freeing of regulation of sawmills increased the demand of wood in Finland, and gave start to significant timber sales in Pekkala estate. The first forest officers were hired in the estate at the time. The first guidelines of forest management for the estate were compiled in 1912, and the first survey of the forests was made in 1916, and repeated in 1922 and 1926. The fellings were planned in consideration of the growth of the forests.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

• Helander, E-mail: ah@mm.unknown

Earlier studies have shown strokes of lightning as the reason for 42% of forest fires in Finland. The frequency in northern Finland has been three times higher than in more southern parts of the country or 1.5 times higher than in Sweden. Taking the climatic factors into account these figures don’t seem to be accurate.

The study is based on the statistics about thunders in northern Finland and the information on the forest fires. We know that though there has been a lightning it is not always that the lighting strikes on land and lights a fire.

From the statistics it can be seen that the most forest fires that are thought to be kindled by lightning, have occurred in the same time when there has been thunder and lighting. Thunders and strokes of lightning striking to the land are the most common reason for forest fires during the warmest summer in northern Finland. The knowledge that a proceeding thunder storm may kindle several forest fires in a row must be acknowledged when planning the fire fighting resources. 

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

• Keränen, E-mail: jk@mm.unknown

The paper describes the history of legislation concerning the use of forests in Denmark. The land area covered by forests has decreased to only 3–4% of the total land area of Denmark already for several hundreds of years ago. Regulations concerning the right to cut forests have been included in the legislation as early as in the 1200s. In 1781 was enacted a decree that stipulated the use of state forests and peatlands. In 1920, a forest act that concerns all the forests in the state was prepared.

• Oppermann, E-mail: ao@mm.unknown

The aim of the study is to define to which extent the productivity of seas in south Finland, and especially the production of animals in sea bottom, can be determined according the forest site classification given to the land areas around the sea, meaning that the productivity class is the same for the forest and the sea. The data for the study has been collected in state owned forests in Evo in middle Finland, in Karelia around the Finnish and Russian border and in southern parts of Karelia.

Where the forests are more barren, VT or Ct types, also the seas have lower productivity, they are oligotrophic or mesotrophic. However, the less barren surrounding forests are not a clear sign of the productivity of the sea. As a result the productivity level of a sea can be estimated relatively good by the fertility of the surrounding areas, though not in all cases. 

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

The PDF contains a summary in German.

• Valle, E-mail: kv@mm.unknown

After the world war one new states were built and they created their own economies and started foreign trade with different products. Timber is one of the traded articles, and not without meaning. New states, Latvia as one of them, have achieved great interest on international timber market, thanks to its favorable transport conditions.

The article presents the main characters of Latvian forests, ownership structure, and the governance related to felling and timber production. Also the most important branches of forest industry are presented. The most important aspects of the Latvian forestry are summarized in the end of article.       

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

• Teikmanis, E-mail: at@mm.unknown

The article describes in vivid style the development of the forest use and the forest science. The work of prof. Cajander is also praised.

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

• Jentsch, E-mail: fj@mm.unknown

Forests and forestry in northern Scandinavia is affected by the climate, as well as economic and demographic questions. In northern Norway the issues of forest management are related to broadleaved forests, in Northern Sweden and Finland, the forests are mainly coniferous. These forests are still mostly primeval forests as the exploitation of the forests have begun slower than in the south. The Finnish forests are mainly owned by the state which makes the challenges of forestry a management problem within the Forest Service. In Sweden, the rational use of forest resources of the north has been lively discussed. Rational management of forests has begun in the southern and central parts of the country, but as the rationalization process reached the northern Sweden, many biological, economic and forest policy problems emerged. This paper outlines the forest resources, forest policy and legislation (so called lappmarkslag, an act that regulate the use of forest in the region) concerning the problems of forest management in northern Sweden.

• Schager, E-mail: ns@mm.unknown

In Sweden lot of state owned forests or earlier mining districts or districts of ironworks have been afforested during the last decade. The amount of afforested areas sinks from south to north. Afforestation has taken place also in privately owned forests.

The article discusses the common economic questions related to afforestation work and the biological viewpoints related to it. The best cultivation methods are presented for several common forest types, such as herb-rich forest types, moss-grown forests types, swampy forests with heavy raw humus and barren pine forest sites (lichen type).

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

• Wibeck, E-mail: ew@mm.unknown

The height growth of Scots pine (Pinus sylvestris L.) seedlings were observed in Korkeakoski and Evo in Southern Finland in 1925-1928. The growth was slow in the beginning of the growing season, increased after that to decrease again towards the end of the growing season. The height growth begun in May, reached the fastest growth rates in June, and ended in June-July. According to the earlier studies, the length of the height growth of Scots pine is dependent on the temperature of the previous summer. This study showed that warm temperatures of the same summer promote height growth, and low temperatures slow it down. Also the daily growth fluctuates, being highest during the afternoon and slowest during the early morning. The daily growth is dependent on temperature.

Norway spruce (Picea abies (L.) H. Karst.) begin the height growth in average 9 days later than Scots pine. Compared to pine, the speed of growth in spruce decreases slower towards the late summer.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

• Hertz, E-mail: mh@mm.unknown

To be able to exactly describe the similarities and differences of vegetation in certain areas, classifying the vegetation only in communities or formations is not enough. Therefore more classes are needed. The classification according the horizontal layers is based on the heights of plants and their relations to each other. Every population in one community has own area of height which extends to horizontal direction.

In comparison with populations the vegetation horizons create a biologically validated comparison of different vegetation groups and their parts. Defining the populations and vegetation horizons creates a division and systematization of plant communities on an ecological basis.       

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

• Kujala, E-mail: vk@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

Natural regeneration has been studied so far mostly on the perspective of regeneration, while the production capacity of the seed crop stand has been of little interest in the earlier studies. This paper studied volume growth of the seed trees and the economic impact of this regeneration method both in a literature review and measuring sample stands consisting of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) dominated stands and mixed forests in Norway.

It is concluded that in the most cases the seed tree stands give better pulpwood and timber yield than the stands in the average. The reason might be that the elite stems can better use their production capacity, and, thus, reach bigger and more valuable dimensions. Even though the growing stock diminishes in the seeding felling, the growth of the stand does not decrease or decreases only little. At the same time, the quality growth improves. In addition, the new tree regeneration is achieved usually without extra costs, and there is no unproductive time period in the stand.

• Barth, E-mail: ab@mm.unknown

The article presents three studies about different aspects of the bio-chemical functions of forest soil. The three studies are i) research on microflora and microfauna of forest soils; ii) study on carbon nutrition of forests in relation to microbial functions of soil and effecting site factors and iii) study on nitrogen metabolism of forest soil. The results of the studies are summarized by every study.

The article discusses the meaning of the results for forest management in practice. The good biological and physiological condition of forest soil is important for the forest growth and it needs to be taken care in regeneration and other forest management. The natural regeneration seems to be better for soil functions. Favoring broadleaved trees as undergrowth enhances the biological processes of forest soil.   

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

• Fehér, E-mail: df@mm.unknown

Different birch species hybridize very easily with each other and identifying the species of an individual tree is difficult. The article gives the description of one variant from Russia and the author suggests naming it after Prof. Cajander.

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

• Sukatschew, E-mail: ws@mm.unknown

Forest site type classification based on the vegetation has not been developed in India. The classifications made by forest officers have been based on the upper storeys of trees. Shrubs have been used to class such sites where grasses are the dominant species. However, some observers in India have used grass and bamboo species to identify sites suitable on unsuitable for certain valuable tree species. In Burma, some bamboo species have been noticed to be good indicators for sites suitable or unsuitable for teak (Tectona grandis L. f.). Studies in the western sub-Himalayan area suggest that certain grasses could be used as indicators for sites suitable for sal (Shorea robusta Gaertn.). Grasses have also been identified as indicators for certain kinds of forests and soils in the area between Ganges and the Jumna.

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

• Osmaston, E-mail: ao@mm.unknown

The paper describes plant species characteristic for ash (Fraxinus exelsior L.) forests in Denmark, and compares the vegetation to beech (Fagus ssp.) forests, the dominating tree species in Danish forests, which have notably simpler ground vegetation. The writer concludes that ground vegetation can be divided into distinct types. Beech grows in several types of soil differing in their fertility (bonitet). The writer has divided the different soil types by their flora (tilstandstyper). The flora is influenced by three factors: climate, fertility of the soil and soil moisture. The paper defines the types of vegetation which describe fertility of the sites (bonitet), and discusses how age, silvicultural condition and tree species affect the vegetation.

• Bornebusch, E-mail: cb@mm.unknown

The article is a congratulatory letter to professor Cajander. The author describes the work of Cajander about forest site classification and its importance to the development of forest sciences not only in Finland but worldwide.

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

• Wappes, E-mail: lw@mm.unknown

• D'Alverny, E-mail: ad@mm.unknown

The article presents middle-European forests and their characteristics, development and use. The main question is whether the current practice of planted coniferous tree forests should be kept or whether more natural mixed forests should be introduced instead. The article discusses the pros and cons of these and the possible felling and management practices.      

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

• Rubner, E-mail: kr@mm.unknown

The result of forest valuation depends heavily on the interest rate and hence determining the rate of interest for forest is the one of the most important tasks of forest valuation.

When defining the interest rate for forests, we need to take into account not only the common interest rate in the country, but also other factors. Those are for example the increase in timber price. By calculating the land expectation value we assume that costs for felling, regeneration and other management will rise by same percent.

The article presents the common formula of land expectation value and discusses its pros and cons. Because of the bad condition of Finnish forests, the forest valuation has not been used widely in practice and hence also the research on theme has been minor. The development of the forests in future will make the theme more relevant. 

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

• Heikkilä, E-mail: th@mm.unknown

The aim of the study was to compare the theories of Soil Rental and Forest Rental. There is a controversy between the theories that is associated to the issues of length of rotation and grade of thinning. For the basis of the analysis was chosen Schwappach’s money yield table for Scots pine (Pinus sylvestris L.) Quality II, published in 1908. Based on the table was calculated the financial yield, the net annual income from a normal forest managed on various rotations, the capital value, and the net income expressed as the rate of interest on the capital value. According to the study, it is the rotation at which any money invested in lengthening the rotation still further, would yield no return. In the case of Scots pine, the highest income is achieved approximately with a rotation of 140 years, and the income per hectares would decrease if longer rotations were used, though the capital invested would increase.

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

• Hiley, E-mail: wh@mm.unknown

The vegetation in the Pacific coasts of British Columbia and Southeastern Alaska resemble the vegetation in the northern Fennoscandia. The national forests have been divided in two parts: Tongass and Chugach national forests. Both of the forests are fairly uniform in their vegetation. The forests have few coniferous tree species as the dominant species from south to north, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemloch (Tsuga heterophylla (Raf.) Sarg.). It is difficult to distinguish forest site types, but it is probable that the forest lands in Alaska and British Columbia could be delimited to similar forest site types as professor Cajander established in Finland.

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

• Harshberger, E-mail: jh@mm.unknown

­In different altitudes of the Mount Fuji in Japan occur succession of different tree species. For instance, at an altitude of 2,000 meters are pure stands of Tsuga diversifolia (Maxim.), under which is generally found young trees of Abies veitchii (Lindl.), but not of Tsuga. Abies veitchii is in its turn replaced perhaps with Larix sp. The succession of the forests of the volcano have reached maturity, which is not the case in the east–north-east flank of the mountain, where the Hōei eruption destroyed all vegetation in 1707. The vegetation had not revived even by the 1920s. The Hōei eruption site is compared to the much faster return of vegetation in mount Krakatau in the warmer tropical region. The succession of forests in the other parts of the mountain is described in detail. Finally, a succession theory is proposed that is opposed to the natural selection theory. The theory suggests that there is an Innermost Factor that controls the plant succession. According to the theory, every species, every formation, should die its natural death owing to the Innermost Factor.

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

• Hayata, E-mail: bh@mm.unknown

The article gives examples of hybridization of forest tree and shrub species in the forests of New Zealand. According to the article, many of the 498 vascular plant species in the forest communities of the New Zealand region must be excluded from the standpoint of hybridism, because they belong either to genera of one species or are unable to cross owing to geographical or biological isolation. The hybrids are in most cases jordanons which cross, and may be more or less distantly related or closely related. The hybrids occur usually in polymorphic groups. Most of the hybrids in New Zealand are fertile. The hybrids can affect the forest communities in two ways; by effecting their composition or their structure. The article includes a list of hybrid groups.

Jubileum publication of professor Aimo Kaarlo Cajander.

• Cockayne, E-mail: lc@mm.unknown

The primeval forests of Scotland were deforested in the Lowlands by the end of 1500th century, and in the end of the 1800th century also the best forests of the more inaccessible Highlands were exploited. The 1800th century witnessed an outburst of afforestation among the private land owners. With help of nursery work and use of exotic species, the work was successful. Silviculture of Scotland would benefit of a reliable method of site classification. The complexity of the geology and topography, and the lack of mature natural stands complicate the establish a forest type classification similar to the one Prof. Cajander has evolved in Finland. The aim is to establish forest site types which include similar types as in Finland, with possibly additional types in the grass-herb series.

Jubileum publication of professor Aimo Kaarlo Cajander.

• Anderson, E-mail: ma@mm.unknown

Severe climatic conditions promote gregariousness, because the number of species capable of surviving is small. Thus, it its more common in cold or arid regions. For instance, sands and gravels that are poor in nutrients, and subject to drying, are often characterized by pure crops of pine, whose seedlings are comparatively drought resistant. One example of gregariousness due to favorable conditions of seedlings, seed-dispersal and germination is birch. It produces seed abundantly from an early age, and the light seeds are dispersed widely by the wind. Gregariousness can also be induced by conditions which destroy all species except those specially adapted to resist extermination. One example of this is annual fires. A species may be gregarious in some conditions and sporadic in others.

• Troup, E-mail: rt@mm.unknown