Population of the Neckera pennata hedw. (Bryophyta, Neckeraceae) in the Syktyvkar city (Komi Republic)

Here we reported new records in the Syktyvkar city of rare moss Neckera pennata Hedw. included in the Red Book of the Komi Republic. The local population of this moss was studied for the first time. Population studies of Bryophyta have never been conducted before in the Komi Republic. In the territory of the recreational zone «Dynamo», we found 92 habitats of Neckera pennata , and six habitats were found in the bordering forest array (bordering site). For each location, we cited data from the herbarium label added with the information about each moss carpet (height above ground level, tree trunk circumference, carpet projection area, exposition, the occurrence of moss-capsules). Total, we studied 219 moss carpets (199 within the ski base, and 20 in the bordering area). The area of moss carpets at the main site ranged from 2 to 450 cm2 (mean area 56 cm2). At older bordering site, moss carpets were larger, from 10 to 511 cm2 (mean area 157 cm2). Total projection area of carpets at the tree trunk was 1,4 m2 (main site - 1,1 m2, bordering site - 0,3 m2). Moss dry weight was 122 g at the main site. The obtained data, after a simple recalculation per unit of area, make it possible to estimate the probable occurrence, projection area and biomass of the species in adjacent forests. Neckera pennata was found mainly in the spruce, mixed and aspen forests of green moss type. We did not find any relationship between the size of moss carpet and the type of forest formation. But, there is a definite relationship between the age of the stand and the area of projection of the moss carpet. Moss carpets establish aspen trunks at a height ranged from 0,2 m to 2,5 m (up to 4 m at the bordering site). The carpets are mainly single. But their number on the trunk increases with the age of the stand under the favorable environment (up to 5 carpets per tree at the bordering site). The trunk circumference in the place of moss carpet establishment ranged from 52 to 197 cm (average 91 cm). Main part of the population is located in the lower and upper part of tree trunks, while the butt-end part of tree (covered with snow in winter period) is less colonized. The carpet occurrence was about the same in the upper and lower part of trunk. But, the moss productivity was higher in the lower part where the largest carpets were registered. There is a tendency of a decrease in the number of carpets and their biomass with a change in exposure from strictly northern, where the maximum of these indicators is noted, towards eastern and western. The illumination of the trunks, as well as the carpet height above ground level, determines microclimate conditions, namely air moisture, which is the most important factor for this epiphytic moss. We found moss carpets not only at the living trees, but also on the dead wood, which indicates the natural dynamics of the population. Neckera pennata in most cases forms monospecies carpets, but we found several accompanying species: Campylidium sommerfeltii, Оrthotrichum speciosum, Pylaisia polyantha, Radula complanata, and Sanionia uncinata . The shape of carpets is ranged, depending on the stage of carpet development, from dot and linear through sickle and reverse-triangular to typical broadly-trapeziform, heart-shaped and broad-renal. We found an impact of air moisture and stand and tree age on the frequency of sporulation. We did not find a clear relationship between trunk diameter and the occurrence of moss-capsules. The correlation between height of carpet location and the occurrence of moss-capsules is insignificant - the share of carpets with moss-capsules decreases with height, which might be connected with the changes in air moisture. Air moisture is also determined the higher frequency of moss-capsules occurrence on the trunks with northern exposition. The composition of stand did not affect the occurrence of moss-capsules. The population of Neckera pennata in Syktyvkar is closed to the populations from the Vologda Region. The differences are due to more severe climate of the Komi Republic. Here, the moss establishes trees with less diameter, forms fewer carpets per habitat and does not from carpets high on trunks.