Functional ecology of lichen Lobaria pulmonaria (L.) Hoffm. in the taiga zone in the European north- east of Russia

The actual information on the functional ecology of the epiphytic large-leaf li- chen Lobaria pulmonaria (L.) Hoffm., a species protected on the territory of Russia and the Republic of Komi, was obtained. Seasonal changes in the lipid and pigment complexes, as well as temperature of water freezing in thalluses were established for the first time. It was shown that the green pigments fund decreases during winter, and reaches the minimum values in spring due to the oxidative destruction of chlorophylls. The fund of carotenoids is more stable. The ratio of unsaturated and saturated fatty acids increases in winter as compared to summer period. The temperature of the water-ice phase transition in winter is reduced by an average of 2.5 ° C and is about -11 ° C. The dependence of the lichen CO2-gas exchange on water content and lighting was studied in the field and laboratory conditions. It was foundthat hydrated thalluses at optimal light-temperature conditions assimilate CO2 at a rate of 3-6 μmol / m2s. In natural habitats, the intensity of CO2 net absorption in thalluses is highly variable and depends on the degree of dehydration. In the warmand dry period of vegetation, positive gas exchange was registered only in the early morning hours, when the thalluses were saturated with vapors of atmospheric moisture. In general, we can conclude that the lichen symbiosis is a fairly stable superorganismic photosynthesizing system. Successful adaptation of L. pulmonaria to habitat conditions and seasonal changes of the main environmental factors is largely due to the functional properties of the lichen. Thanks to this, the lichen is wide- spread in the taiga forests of various formations, reaching the maximum abundance in the old-growth aspen forests, spruce forests and floodplain tree-like willows. The data obtained should be taken into account when taking measures to protect and monitor L. pulmonaria populations, predict the species status in the conditions of global climate change and disturbed habitats.