Current issue: 54(1)
Under compilation: 54(2)
The plant populations of Finnish open bogs are typically formed of two layers. The layers normally consist of one or rarely two species. The structure of plant populations in open bogs is a consequence of the development where determining factors are different site requirements of the species, and the differences in the biotic vitality and capacity for reproduction.
Phytogenesis should be taken as a basic unit for describing the plant societies or vegetation of treeless bogs. However, acknowledging the sub-populations may be of advantage for describing the ecological, genetic and regional characters of open bogs.
The basic classification of open bogs must be done based on the ground layer. The more detailed classification follows mostly based on field layer, partly also based on the ground layer.
The PDF contains a summary in Finnish.
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.
The paper studies the relationship of settlements to the forest types and forest soil. The observations have been done and data collected in southern Finland, around lakes Päijänne and Saimaa during summer 1917. Because of the shortcomings in the data, the results in the paper can be seen only as indicative.
The settlements have spread out firstly to areas of grove alike soils and herb-rich forests. The human settlements are still on these days concentrated on those areas. When more land is needed for agricultural purposes, the more fertile areas were introduced first. With forest type classification this means moving from herb-rich Oxalis-Myrtillus-type to Pyrola-type and to some extent Myrtillus-type. The more barren types are used as fields only very seldom. The differences in the fertility of the soils affects strongly the welfare and development of the people and the communes.
The study shows that when considering the soil and vegetation, preconditions for agriculture are very different in different part of Finland. Also the climate and the geographical characters vary. To win more agricultural land, the fertile peatlands should be considered.