Ecological and cenotic characteristics of communities involving the species of Prunella vulgaris L. and Prunella grandiflora L. in the Middle and Southern Urals

. On the territory of the Middle and Southern Urals, P. vulgaris is found in pine, spruce-pine, birch forests, meadows and in artificial spruce-larch forest plantations; P. grandiflora - in birch forests, less often on meadows. P. vulgaris is confined to half-open places or light-forest with moistening from sub-forest-meadow to wet forest-meadow with not very rich or rather rich soils. P. grandiflora grows in semi-open spaces and in light forests with moistening from wet-steppe to dry-forest-meadow with rather poor soils. Both species are found on very poor soils and the ones that are poor in nitrogen, having a weak acidic and acidic soil medium. According to the soil acidity factor, the amplitude of the ecological space of P. grandiflora coenopopulations on studied territory goes beyond the ranges of the ecological range according to the scales of D.N. Tsyganov.

(Hd), soil trophicity (Tr), available nitrogen content in soil (Nt), soil acidity (Rc), and habitat shade (Lc). The assessment of the environmental factor in points was calculated by the generally accepted method [6][7]. Based on 20 descriptions (7 of which with P. grandiflora, 13 with P. vulgaris), 2 dendrograms of the similarity of the communities under review for each of the studied species were constructed. At the clustering level of 1,2, one description (the 2nd cluster) represented by a closed birch forest, separated from the second branch. The community is described 2 km northeast of the Sverdlovskoye village, Krasnoufimsky district of Sverdlovsk region, the southwestern slope of the hill (steepness of slope 30°). The tree layer is formed by Betula pendula (projective cover of 45%) with a slight admixture of Populus tremula. Herb layer is well developed (projective cover of 90%), 60-70 cm high, has 44 species per 100 m². Herb layer is dominated by Rubus saxatilis (10 %), Festuca pratensis (8 %), Calamagrostis epigeios (7 %), Brachypodium pinnatum (7 %). The projective cover of P. grandiflora is 3%. The species at this point is located on the border of its range and forms a local shrinking population.
The 3rd cluster combines sparse birch forests (Betula pendula), bordering meadow edge communities. Tree layer projective cover is up to 30%. Polygonatum odoratum (2 %), Vicia cracca (2 %). The projective cover of P. grandiflora varies from 4 to 12%. The abundance of P. grandiflora in these habitats cannot be called the highest, but the habitats are the most characteristic for this species.
The dendrogram of community types involving P. vulgaris (Fig. 1B) divided into two branches at the clustering level of 1,7. The first branch united birch forests and meadow communities near the birch forests; the second -pine, spruce-pine forests and spruce-larch forest plantation. Each of the two branches was divided into 2 clusters (community types).
The 1st cluster unites birch forest communities. The tree layer is represented by Betula pubescens with a slight admixture of Populus tremula and Sorbus aucuparia. The projective cover of the tree layer is from 30 to 40%, 10-12 m high, with a trunk diameter of 15-25 cm. The shrub layer is poorly developed and is formed by the Salix caprea. Herb layer is dense (80-85%). The dominant is Prunella vulgaris (7-8%), codominated by The 3rd cluster is represented by the description from Perm region, near the Altynnoye village -spruce-larch forest plantation mixed with Sorbus aucuparia and Padus avium. The tree layer density is 50%. The projective cover of the grass layer is 60%. 41 species have been marked at the area of 100 m². The herb layer is dominated by Artemisia vulgaris (5 %), Chamaenerion angustifolium (7 %), Dryopteris carthusiana (5 %), Dryopteris filixmas (5 %), Fragaria viridis (5 %). Projective cover of Prunella vulgaris is 5%.
The data we obtained for P. vulgaris and P. grandiflora species according to ecological scales allow us to compare with those previously established by D.N. Tsyganov [5] for the European part of Russia and the Urals. It turned out that the species studied within the Middle and Southern Urals are characterized by a relatively narrow range of ecological space according to the considered ecological scales. For most factors, the amplitude of the ecological space of the studied species of the genus Prunella in the territory covered occupies the middle part in the amplitude of the ecological space of the species and does not go beyond the ecological range of species according to the scales of D.N. Tsyganov [5].
In terms of soil conditions, the P. vulgaris species reaches its potential to its fullest in relation to soil moistening factor and less in the richness of nitrogen in the soil. P. grandiflora for the totality of soil conditions most fully realizes its potential in relation to the factor of soil moistening and less -in acidity. At the same time, according to the acidity of the soil, the species occupies an extreme position -6-6,7 points (7-11 on D.N. Tsyganov scale) and goes beyond the ranges of the ecological area on the scales of D.N. Tsyganov, which is probably due to the presence of P. grandiflora on the northern boundary of the range. P. vulgaris in the Middle and Southern Urals grows in habitats from well shaded to poorly lighted ones, on soils with sufficient moisture and nitrogen content. While P. grandiflora prefers drier and lighter habitats, with less rich soils and low nitrogen content. On the territory of the Middle and Southern Urals, P. vulgaris is found in pine (Pinus sylvestris), spruce-pine (Pinus sylvestris), birch (Betula pubescens) forests, in meadows and in artificial spruce-larch plantations. P. grandiflora coenopopulations are found in birch forests (Betula pendula), and are less common in meadows, which is probably related to the position of this species on the northeastern boundary of its range.