Current issue: 55(2)
Under compilation: 55(3)
The size of the field and the ditching on it as well as the condition of the field at the time of the surrender of Porkkala area (from Finland to Russia) play an important role on how far the natural regeneration of the fields has progressed.
Larger open fields have naturally regenerated only on sides where the surrounding forest can spread the seeds or the thicket of saplings has reached, whereas small parcels of fields have normally been fully forested. Most important species have been e.g. silver birch and pubescent birch, grey and common alders and European aspen as well as pine and spruce. The broad leaved species are dominant.
The PDF contains a summary in Finnish.
The article presents the background of increment calculations and periodic measurements of forests, as well the historical development of increment calculations in North-America, Middle-Europe, Scandinavia and Finland. The measurements and calculations are presented for individual trees, for a forest stand and for the total resource of a normal forest stand.
The practice of increment calculations has still some problems regarding the measurements of standing and harvested trees. The article discusses some ways to overcome the problems.
Volume formulas have been developed already for long time but there are still some questions to be solved. The volume of a stem can be calculated based on measurements of diameter on various heights or based on mathematic formula. The article presents the formula development for that. The study is based on measurements of 24 pine stands.
The results of the new formula can be seen satisfactory with the relatively small data of this study. Coincidentally the formally best mean solution of the here compared volume calculation formulas was the one based on Denzin’s formula. There the deviation from total mean is almost zero.
The article discusses the growth factors, the influence of the seed tree to the seedlings and the relations of the trees within one age class in sense of growth of the trees and their effect for practical forest management.
The author concludes by noticing that there is a remarkable gap in knowledge about growth factors and more research is needed especially on the interactions of various growth factors. Earlier research on forests has not taken the characteristics of the site and its effect into account adequately. In addition to the observations in the nature, the individual growth factors and their interactions should be studied quantitatively.
The study presents and describes the abundance and distribution of tree roots in specific stands of heathy forest types in Lapland. The data was collected in the Sodankylä commune.
Due to the shortcomings in the data, conclusions can be drawn only regarding pine forests. The result of study states that the root competition plays an important role in the development of the forests, and most of the other observed phenomena are linked with root competition. The more infertile the soil the vertically and horizontally wider and more abundant the root system. It seems that the abundance of the root system is similar in forest of same fertility class and same density and age.
Understanding the growth of trees is the prerequisite for meaningful forest management. Hence the studies on the ways the trees grow is important. The growth of roots and sprouts was studied by Larix leptolesis, Pinus silvestris, Betula pendula, Robinia pseudoacasia, Populus euramericana, Pseudotsuga taxifolia, Quercus borealis and some other species. The results of still ongoing experiments on pine, birch and larch are presented for root and shoot growth.
The results indicate that the amount of light or shade the tree is having plays an important role in the growth. Hence some tree species are better adapted to shade than others, there are differences in their growth depending whether they are in light or in shade.