Species and coenotic diversity of fir (Abies sibirica) forests in foothill and mountain landscapes of the Northern and Subpolar Urals

The plant cover of the western macroslope of the Urals was studied by the researchers from the Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences since 1989. Investigations, that were carried out in the basin of the Unya river, Pechoro-Ilychsky biosphere reserve and national park «Yugyd va», allowed to obtain information on the structure, dynamics and species diversity for so far poorly studied fir (Abies sibirica) forests within the foothills and mountain zone of Northern and Subpolar Urals (Degteva, Dubrovskiy, 2014).

Standard methods adopted in geobotany and forest typology (Ipatov, Mirin, 2008) were used, including Ipatov’s abundance scale for species in herb-dwarf shrub layer assess, at 79 sample plots of 400 m² size. The data of 32 relevés kept in the phytocenarium of the Institute of Biology were taken into consideration. The level of α-diversity of vascular plants was assessed as a mean value of species number per plot. Ellenberg’s ecological scales (Degteva, Novakovskiy, 2012) adopted to the study area were used in assessing the relations of vegetation and main environmental factors (humidity, soil nutrition, soil acidity and illumination). Data processing was performed using the statistical packages SPSS and PC-ORD (McCune et. al., 2002).

Coenoflora of fir forests of area in question includes 169 vascular plant species from 102 genera and 43 families. The leading families are Asteraceae and Poaceae. Species from 16 eco-coenotical groups are present in the coenoflora with 47.1 % belonging to "valley" eco-coenotical group and 29.7 % to taiga-forest one; 8 species are included into the Red Data Book of the Komi Republic.

The stands composed of trees of VIII–IX age classes are complex (eight tree species) and have relatively low total canopy density. The first canopy layer of 0.2–0.5 density is dominated by Abies sibirica and sometimes by Picea obovata (up to 7 points) with constant admixture of Betula pubescens and Pinus sibirica (up to 2 and 1 points respectively). In the valley ecotopes height of trees in the upper stand layer is 22–26 m, stem diameter is 20–50 cm. Abies sibirica dominates in the lower stand layers (up to 8 points). Coniferous undergrowth is active, while the other tree species are restored weakly. The crown understory density is 0.3. Most abundant among 16 species are Sorbus sibirica, Rubus idaeus and Rosa acicularis.

According the Ellenberg’s scales the various types of fir forests are different in relation to such ecological factors as soil nutrition and soil acidity, while their dependence of soil moisture and light regime is minimal. DCA ordination gives similar results. Soil nutrition and soil acidity are the main environmental factors affecting vegetation variability. Factors of soil humidification and light conditions do not show significant correlation with any ordination axis.

Fir forests of green moss type are typical for the river terraces, tops of the hills in the foothill belt of the Northern Urals. In this type four associations (Abietetum myrtilloso-hylocomiosum, Abietetum myr­tilloso–gymnocarpioso-hylocomiosum, Abiete­tum oxalidoso-hylocomiosum, Abietetum ruboso saxatilis–hylocomiosum) are determined. The first one is central, ass.Abietetum ruboso saxatilis–hylocomiosum is defined for the first time for the Komi Republic. The latter association is a part of the boreal small herbal cycle of wet forests that also includes Piceetum ruboso saxatilis–hylocomiosum and Po­pu­letum tremulae ruboso saxatilis–hylocomiosum. So far there is no information on similar syntaxa on vegetation of the Urals, Siberia and Transbaikalia regions.

Five associations of herbal type (Abietetum gymnocarpiosum, Abietetum phegopteridoso–dryop­teridosum expansae, Abietetum diplaziosum sibirici, Abietetum athyriosum distentifolii and Abietetum aconitosum) cover slopes of the mountains and hills with by higher soil nutrition. Two of these (Abietetum gymnocarpiosumиAbietetum athyriosum dis­tentifolii) are new for the region.

Key words: forest vegetation, fir forests, Northern and Subpolar Urals

Section: Articles

How to cite

Degteva S. V., Dubrovskiy Y. A., Novakovskiy A. B. 2016. Species and coenotic diversity of fir (Abies sibirica) forests in foothill and mountain landscapes of the Northern and Subpolar Urals // Vegetation of Russia. N 29. P. 3–20. https://doi.org/10.31111/vegrus/2016.29.3

Received April 13 2016

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