Huge lung lichens prove clean air in Bosnia´s Una National Park (27.03.2009)
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Bilovitz, Türk & Mayrhofer 2009: Lichens from the Una National Park
Lichens are an integral and important component of our ecosystems. The largest biomass of lichens occurs in old-growth forests with clean air quality. Lichens possess a number of characteristics that make them suitable biomonitors for air pollution. Many lichen species have large geographical ranges, allowing study of pollution gradients over long distances. Lichen morphology does not vary with the seasons, and accumulation of pollutants can occur throughout the year. Lichens are usually very long lived. But most important: Lichens are excellent biomonitors due to their sensitivity to pollution.
Due to declining population, the lung lichen (Lobaria pulmonaria) is considered to be rare or threatened in many parts of the world. The decline has been attributed to industrial forestry and air pollution, particularly acid rain.
Our last trip to Bosnia unveiled the clean air in the untouched old-growth forests of Una National Park in the Northwest of Bosnia and Herzegovina. At the end of March 2009 we explored the area around Veliki Ljutoc mountain (elevation: ca. 900 m). We discovered trees looking like remnants from pre-industrial times. Beside a rich lichen flora these trees were covered by very old and huge lichen of the rare lung lichen (Lobaria pulmonaria). Intact lichen bodies (thalli) of this enormous size have just survived where for decades neither air pollution nor forestry afflicted the forests. In Germany lung lichen of this size vanished a very long time ago.
Thanks to Mag. Dr. Bilovitz (Institute of Plant Sciences Karl-Franzens-University Graz, Austria) and Prof. Dr. Türk (FB Organismische Biologie Universität Salzburg, Austria), who determined samples of collected lichen, we have the proof that Lobaria amplissima is growing on this tree too. Lobaria amplissima is one of the most threatened lichen species all over central Europe, and is cited in most Red Lists as either extinct or critically endangered (e.g. TÜRK & HAFELLNER 1999, WIRTH et al. 1996). Before 1900, it was rather widespread in Germany, and was known from over half of the Federal States. In the 20th century, it has only been found in the southernmost regions of Baden-Württemberg and Bavaria, and since 1975 it has disappeared from many localities, including the last known one in Bavaria.
The reasons for the decline of this and other Lobarion species have been thoroughly investigated, as this is the most threatened lichen element throughout (APTROOT & ZIELMAN – Herzogia 17/2004). Air pollution by sulphur dioxide has unquestionably had a harmful effect, but changes in forest management are often also provided as explanation. Recent research has shifted towards population studies, as individuals of the Lobaria species, and especially Lobaria amplissima, are thought to be long-lived (in the order of a century and more), as can be deduced from the often large thalli and the minimal yearly radial growth. In general, habitat continuity seems to be a prerogative for the survival of Lobarion species.