Seasonal growth of Abies Mill. species introduced in the Boreal Zone (Karelia)

The study of the growth of the introduced species of Abies was carried out in the Botanical Garden of Petrozavodsk State University (middle taiga subzone, southern Karelia). Studies have established that the growth of shoots of species of the genus Abies begins at the same time in years with a friendly spring. In years with a protracted spring, differences between species in the timing of the onset of this phenophase can reach 1 week. The differences in the timing of the termination of shoot growth also do not exceed 1 week. Growth culminates first in A. holophylla, and most recently in A. balsamea. The highest value of the maximum growth is characteristic of A. holophylla, in other species it is 10-20% less. It turned out that the beginning and culmination of growth in them mostly depends on the temperature regime of the air. The air humidity and the amount of atmospheric precipitation constantly exceed the optimal value for this process. It was found that the beginning of the growth of the needles of the studied species of the genus Abies is noted in late May-early June. The differences do not exceed 2-4 days. First of all, the culmination of the growth of needles is noted in A. holophylla and A. concolor. Its value in these species is 1.5-2 times higher than in other species. Studies have shown that the timing of the beginning, culmination and end of needle growth under the influence of environmental factors from year to year can vary within 2-18 days. The beginning of the growth of needles depends on the temperature regime of the air, and the growth dynamics, in addition, on the humidity of the air and atmospheric precipitation. The nature and degree of influence of environmental factors on the growth of needles varies very slightly from year to year, but differs markedly in the studied species of the genus Abies. It was found that A. sibirica and A. balsamea should be recognized as the most promising for landscaping settlements in settlements (with a low degree of pollution by pollutants).