GRID MAPPING IN STUDYING THE DISTRIBUTION OF LICHENS OF THE GENUS USNEA (AS APPLIED TO THE TERRITORY OF THE MOSCOW REGION)

Abstract

The literature review and analysis of a herbarium of fruticose epiphytic lichens Usnea (genus: Usnea Dill. Ex Adans.) from 450 points located in the Moscow region (Moscow Oblast – MO) showed the presence of five species in the territory. These species can be found on branches of spruce and pine, less often – birch, some finds are noted on black and gray alder, rowan, and willow. The emergence and development of Usnea in MO is possible strictly in the presence of certain conditions. Firstly, certain microclimatic parameters are required such as sufficiently high humidity of the surface air layer and minimal indicators of tropospheric pollution (absence of harmful compounds and of a high content of dust particles). Secondly, certain groups of plant communities, old-growth forests, and suitable phorophyte must be present. Schemes provided in the article demonstrate the locations of maximum diversity and individual finds of Usnea species per 100 km2 on the study area. The richest diversity of Usnea species is found in the Lotoshino and Taldom districts and at the intersection of the Volokolamsk, Ruza, and Istra districts, where there are no large polluting industrial objects and, according to ecomonitoring data, the air quality is the highest (with the lowest levels of harmful substances and dust particles). Usnea hirta and U. dasopoga are most widespread species of the genus Usnea in MO. Usnea lapponica and U. glabrescens are the rarest species, U. subfloridana is relatively rare. The reliability of the habitat of U. florida, U. glabrata in MO has not been confirmed yet. Usnea species are mainly present in the western and north-western portions of MO. These lichens are rarely found in the south-eastern portion of MO and on sites near big cities. Ecologically Usnea lichens gravitate toward wet and waterlogged old-growth coniferous forests, glades, and small foliar trees along river valleys, as well as edge parts of forested marshes and raised bogs. In these landscapes, the thallus of Usnea reaches the maximum size. Usnea species occur frequently and cover abundantly tree branches and trunks with multi-species sets of 2–4 epiphyte lichens (including species from other taxa). Thus, the ecological situation in the western and north-western portions of Moscow Oblast can be concluded to be favorable.