Notes on Lecania in Eastern Europe and Central Asia

More documents

Recommendations

Info

40 Lars Borg and Margit Aronsson GRAPHIS SCRIPTA 16 (2004) Table 1. The total number of trees of the different tree species, which were included in the investigation, and the occurrence in percent of the different lichen species on these tree species. Tree species Number of trees Anaptychia ciliaris % Pleurosticta acetabulum % Ramalina fraxinea % Acer platanoides 180 36 11 54 Acer pseudoplatanus 7 0 0 43 Aesculus hippocastanum 21 0 0 14 Fraxinus excelsior 76 41 12 68 Quercus robur 164 2 0 34 Tilia cordata 107 3 5 22 Ulmus glabra 70 40 4 44 preferred pH-range in the bark is 6–7 for P. acetabulum and A. ciliaris while R. fraxinea has a range from 5–7. This supports the results from the present investigation with a broader amplitude for R. fraxinea. Anaptychia ciliaris and Pleurosticta acetabulum are more common on trees with higher pH-values. The only thing that deviates from the expected distribution is that P. acetabulum has a more limited abundance compared to A. ciliaris. The girth. All three lichen species showed a predominant presence on large trunks (Table 2). The correlation was statistically significant for A. platanoides with P. acetabulum and A. ciliaris (z-test p
GRAPHIS SCRIPTA 16 (2004) Population size and ecology 41 Table 2. Average girth in cm for trunks with and without Anaptychia ciliaris, Pleurosticta acetabulum and Ramalina fraxinea respectively. The standard deviation is put in brackets. Tree species/ With Without With P. Without P. With Without trunk girth (cm) A. ciliaris A. ciliaris acetabulum acetabulum R. fraxinea R. fraxinea A. platanoides 1.65(0.46) 1.53(0.51) 1.83(0.60) 1.55(0.48) 1.66(0.48) 1.49(0.50) F. excelsior 2.35(0.74) 2.04(0.51) 2.42(0.65) 2.15(0.64) 2.24(0.71) 2.03(0.33) Q. robur 0 0 0 0 2.52(0.92) 2.56(0.91) T. cordata 0 0 0 0 2.07(0.49) 1.81(0.62) U. glabra 1.67(0.44) 1.99(0.77) 0 0 2.18(0.76) 1.65(0.52) of the five avenues along asphalt roads were asphalted 1980 and 1984 respectively, 2) the contribution of dust from the arable fields is enough for these species, 3) the dust is less important on trees with a natural high bark pH as A. platanoides and F. excelsior. On the contrary, Lundbladh & Milberg (2003) found that both R. fraxinea and P. acetabulum were positively correlated with gravel roads and A. ciliaris with asphalt roads in a study on A. platanoides and F. excelsior in Motala county. Occurrence of apothecia. About 75 % of the individuals of A. ciliaris and R. fraxinea had apothecia compared with about 50 % of the individuals of P. acetabulum. In the Swedish lichen floras (Ursing 1976 and Moberg & Holmåsen 1982) apothecia is said to be often present on all three species. Conservation aspects. Göransson (2003) presents A. ciliaris as the perhaps best signal species in Skåne for high lichen species number in churchyards and similar biotopes. Table 3. Presence in percent of total presence for Anaptychia ciliaris, Pleurosticta acetabulum and Ramalina fraxinea in different aspects on the tree trunks. W, NW wet, shade N, NE, E medium S, SW, SE dry, sunny A. ciliaris 22 38 40 P. acetabul. 17 26 57 R. fraxinea 28 38 34 Among environmental factors which creates a high lichen species number are the number of tree species, the number of large tree trunks and a high yearly precipitation (Göransson 2003). Applying these criteria to this investigation except high yearly precipitation (precipitation is about the same in the investigation area) the following two avenues and one churchyard appear to be as the most valuable: Björnö farm avenue (locality number 1, in Fig. 1). 9 different tree species, 98 trees with a girth >2 m and 17 individuals of A. ciliaris. Läckeby farm avenue (locality number 4, Fig. 1). 4 different tree species, 6 trees with a girth >2 m and 46 individuals of A. ciliaris. Ljungbyholms churchyard (locality number 9, Fig. 1). 5 tree species, 6 trees with a girth >3 m and 3 individuals of A. ciliaris. In all these three localities Bacidia rubella was found. B. rubella is considered to be a signal species for high lichen species number in churchyards and similar biotopes in Skåne (Göransson 2003). Conclusions The size of the populations of Anaptychia ciliaris and Ramalina fraxinea fits with expectations according to literature, while Pleurosticta acetabulum has a smaller population than expected. Also the ecology of P. acetabulum deviates from the expected. This may be a local deviation, not recognized earlier, however, it seems more likely that P. acetabulum narrows its ecological nisch to the most favourable substrates (A. platanoides and
Page 1 and 2: Population size and ecology of Pleu
Page 3: GRAPHIS SCRIPTA 16 (2004) Populatio

Notes on Lecania in Eastern Europe and Central Asia

Create successful ePaper yourself

Delete template?

Save as template?