Publication details
Effect of air pollution on species composition of communities of epiphytic bryophytes with respect to bark chemistry
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| Year of publication | 2019 |
| Type | Appeared in Conference without Proceedings |
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| Description | Epiphytic bryophytes are susceptible to air pollution. Disappearance of sensitive species from highly polluted areas and their return after decrease of pollution load was recorded during the second half of the 20thcentury in Europe as well as in recently polluted industrial areas. However, effect of air pollution on epiphytic communities composition and the associated role of host tree bark chemistry has not been sufficiently explored. The main aim of our study was to assess the effect of air pollution on the structure of epiphytic bryophyte communities hosted by tree species with different bark pH. Due to higher buffering capacity of basic substrates, we expected smaller difference between communities on host trees with higher bark pH in areas with distinct pollution loads. Epiphytic bryophytes were studied on 50 study sites with similar climatic conditions but contrasting levels of air pollution (based on model data of SO2 and NOx loads) in Central Europe. All species of bryophytes and their abundances were recorded on the five trunks of oaks (Quercus robur or Q. petraea, lower bark pH expected) and five ashes (Fraxinus excelsior, higher pH expected) from the ground to 2 m height at each study site. Additionally, four phytosociological relevés 25 × 25 cm were recorded on all trees. As a proxy for the current pollution load at each site, thallus N concentration was measured in Hypnum cupressiforme or H. andoi. We recorded 89 species of bryophytes in total. Epiphytic communities are more species-rich in areas with low levels of air pollution both on oaks and ashes. Air pollution was found to be a significant environmental variable explaining part of variability among studied communities. Bark pH and N concentration in Hypnum thalli corresponded to model data of SO2 and NOx loads. Bark pH range was shorter on ashes, acidifying impact of pollution was buffered partially. Species composition of communities on ashes differed only under the highest SO2 load, on the contrary, oak communities were affected by high level of any pollutants as the bark become more acidified. Air pollution thus determines the structure of epiphytic bryophytes communities. |