THE LOBARION, AN EPIPHYTIC COMMUNITY OF ANCIENT FORESTS THREATENED BY ACID-RAIN

Lobaria pulmonaria and other members of the Lobarion were found to inhabit drainage channels below old and large wounds on the trunks of various deciduous trees in stands of long ecological continuity in a forest reserve dominated by Picea abies in southeastern Norway. Such channels were richer in minerals and had a higher pH than normal bark, which was covered with more acidophyticepiphytic communities, mainly the Pseudevernion. Chemical microhabitat differentiation was most clear in edaphically poor sites. The restriction of a previously ubiquitous Lobarion to mineral-rich microsites on stems if probably an effect of acid rain. Since acidification seems to make the Laborion more dependent upon old and damaged stems, modern forestry probably aggravates the damage caused by acid rain.