Aktywność żerowiskowa nietoperzy w różnych fazach rozwojowych drzewostanów sosny zwyczajnej

Scots pine (Pinus sylvestris L.) is economically the most important tree species in Polish forestry. Congeneric pine stands have a quite low level of biodiversity, and logging with clear sites may even cause their further decline. It is very important to discover the influence of clear−cuttings in managed pine stands on different groups of organisms. One of them are bats which play an important role in forest biotopes as a regulator of insect pests. The aim of this paper is to compare the foraging activity of bats in pine stands of different stages of growth. The study was carried out in three complexes of pine forests in western Poland: Drawska Forest, Notecka Forest and Dolnośląskie Forests. Four types of growth phases were studied: clear−cut sites (Z), young plantations in the age 2−5 years (U), 41−60−years−old stands (III) and mature stands in the age over 80 years (V). The study of the foraging bat activity was conducted with broadband ultrasound detectors Pettersson D−1000X within 3 hours after sunset in summer periods of 2013 and 2014. The recordings were analyzed with BatSound software. Total 19 180 bat passes were recorded on all 120 sampling plots. 11 bat species: Nyctalus noctula, Pipistrellus pipistrellus, Eptesicus serotinus, P. nathusii, Myotis myotis, P. pygmaeus, M. nattereri, Barbastella barbastellus, N. leisleri, E. nilssonii and Vespertilio murinus and four groups of species: NEV (Nyctalus, Eptesicus, Vespertilio), MSP (Myotis), PSP (Pipistrellus), and PLE (Plecotus) were recognized (tab. 1). The dominant was common noctule N. noctula (71.5%). The highest foraging activity of bats was recorded in open areas: clear sites and plantations (fig. 1), next in mature stands and middle−aged stands. The obtained results suggest that bats can adapt to a mosaic of habitats created by clear−cutting harvesting system in managed pine forests.