Scientific publications

The distribution of each plant species over the Earth surface is close associated with environmental gradient. In habitats artificially selected for studying the several types of species expression are represented. In the first type of expression only the peak of species distribution is included into. In the second type the most part of spectrum of species distribution is within the environmental gradient and in the last type the whole spectrum included into the range of gradient.

Leaning the written above we can define the problem of biodiversity preservation as a problem preserving the habitats of living organisms. One of such types of habitats in Taiga zone of Baltic region are the old growth forests (OGF). At present the intensive utilising the forest resources is occurred and the important problem of preserving the areas of OGF as habitats of certain species is solved.

In Russian references we did not find descriptions of old growth forests. Our research group carried out investigations in two areas of Russian Karelia: Pudozh and Medvezhegorsk areas. The aim was description followed by characteristic of OGF. The areas and particular plots for investigations were chosen basing the earlier developed criteria, such as:

the distance from permanent human settlements;

the absence of visible human impact (logging traces and recreation pressure...);

the absence of fire traces;

significant prevalence of young stage trees number over the older trees;

the presence of several levels in the forest structure;

the number of dead trees should be over 20 % of total number of live stems.

Study areas were selected according the mentioned above criteria. They were described using the appropriate methods based on the wildly used techniques for describing the vegetation.

We got the next data characterising the phytosociology of spruce OGF in the middle Taiga zone. Thus the mean age of spruce was 125+-23,2 years and the total range of age fluctuation was 70-220; coverage area of canopies of tree level was 55+-9,0% (30-85%); total number of trees on 400 m2 study area was 22+-4,7 (12-44); number of shrub species on 400 m2 study area was 3,9+-0,85(1-6); number of vascular plants species on 400 m2 study area was 20+-3,9 (11-38); percentage of dead trees was 87+-24% (45-133%) of total number of live stems. Besides the result of analysis with Braun-Blanke method was a list of 15 species of vascular plants typical for spruce OGF. However these species are also typical in other spruce forests, pointed in references.