Effect of forest fragmentation on the epiphytic lichen cover of pine trunks on the example taiga town Влияние фрагментации местообитаний на эпифитный лишайниковый покров сосны на примере таежного города

The main characteristics of epiphytic lichen cover on pine trunks depending on the area of natural pine forest in Kostomuksha (north Karelia) were analysed. The town of Kostomuksha was built so that to provide the conservation of forest sites. 56 fragments with the area of 0.04 - 6.13 ha were studied. The average area of fragment is 0.62 ha, with 49 fragments (88%) having the area less than 1 ha. Biodiversity and lichen cover were studied in the each fragment with using framework 10x20 cm. 1792 sample plots were made on 448 trees. The total lichens cover varies from 0 to 85%,averaging 10%. 25 species of lichens were found. The number of species in the sample plots varies from 0 to 9. Dominant species found are Hypogymnia physodes, Parmeliopsis ambigua, P. hyperopta, Imshaugia aleurites, Cladonia. Species Alectoria sarmentosa, Cladonia macilenta, Pseudevernia fufruraceae, Bryoria fremontii were less common. It was shown that the main parameters of lichen cover are closely related to the size of the area left in the city forest fragments. The maximum values of species diversity and cover of lichens were found in the fragments of more 1-2 hectares. Проанализированы основные показатели эпифитного лишайникового покрова стволов сосны обыкновенной в зависимости от площади естественных сосновых сообществ, оставленных на территории г. Костомукши. Показано, что основные параметры лишайникового покрова тесно связаны с площадью оставленных на территории города фрагментов леса. Максимальные значения показателей видового разнообразия и покрытия лишайников встречаются во фрагментах сосновых сообществ площадью более 1-2 га.