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150 NO, x 10{ m-2 x YQar'' (Ldnsstyretsens NaturvArdsenhet in Malmohus liin, pers. comm.). J'hese figures, which are cafculated for open areas without trees, are based on measurements from S6derAsen, NW SkAne, made by Institutet f6rVatten- och LuttvArdsforskning. The maximum and the maximum of the monthly mean values of the SO, and NO, content in the air during 1986 and 1987 from the SdderAsen locality are shown in Table Z. For comparison, the corresponding values for Bredkiilen, in the province of J5mtland in central Sweden, are also included. The amount of other nitrogen oxides is negligible in relation to the amount of NO. (Dahlberg et al. 1 987, Lovblad et al. 1986). Table 1. pH values determined in November lggg at Romeleklint. Amphibolite Hyperiledyke cement found. soit Surface4-5564 fnsiderock 54 7 t0 Table 2. Measurements of SO. and NO, content from SOderAsen, NW SkAne (50 km lrom the locality) and Bredkilen, 80 km NNE Ostersund in Jdmtland (centralsweden), made by lVL. Maxirnlm values for 1986 and 19g7, and the maximum of the monthly mean values are indicated. pg SO/rP air, max. value max. of rnonthly mean value pg NO/rP air, max. value m€u. ol npnthty mean value Material and methods S6derAsen: 1986 1987 51.8 155.6 8.7 17.8 9.2 12.6 2.3 4.0 Bredkilen: 1986 1987 11.2 13.1 2.3 2.9 5.0 3.2 0.8 0.7 Six people took part in the investigation and the area was visited lour times. The material collected is deposited in LD. The scientific names accord with Santesson (1984), except tor Placynthiella icmalea(Ach.) Coppins & P. James, Trapelia placodioidesOoppins & p. James and Porpidia Kdrb. (= Huilia). Most lichen species occur in a specific pH interval of their substrate. Wirth (1980) set up pH classes and presented pH intervals within which the ditferent species occur. The interuafs otten include more than one pH class, €. g. Lepraria incana which octurs in pH classes z4,which means pH 3.4-5.6 (see the bottom of Table 3). We have compared the distribution into pH classes between the lichen flora found in 1 939 and the lichen flora f rom 1986-88. Two hypotheses were tested. 1) The present lichen flora occur within the same pH classes as the one from 1939, using 1, test (Clarke19B0) and Mann-Whitney U test conected forties (Siegal 1 956). 2) The vanished species occurwithin the same pH classes as the remaining ones, using X'test. Since the pH value of the substrate has decreased between the two studies (see above) only the lowest pH class for each species was used in the calculations. Results The species found in the two investigations, and the pH intervals within which they occur,
151 are presented in Table 3 and 4. In 1939, Degelius found altogether 57-59 species (using recent taxonomy), while the number of species in our investigation is 54- 17 of them are new, while 20-22 of the species found in 1939 were not {ound again. The two hypotheses (see Material and methods) were both rejected at the 2-5"/" level. Thus, the present lichen flora prefers or tolerates a lower substrate pH level than the flora of 1g39, and the species which prefer or tolerate a less acid substrate have vanished. Discussion Methods The investigation of 1939 was carried out in a few hours, but this was probably compensated for by the great floristic knowledge of the excursion members. During the present investigation more time was spent and more people took part.The species found by us but not by Degefius et al., were in 1939 eitherabsent or present but not observed. Thus, it is easierto draw conclusions about the species found by Degelius, since theywere particularly looked lor during the present investigation. Degelius mainly mentioned the abundance of some conspicuous species, but since he did not use standardized methods we will only discuss them in a few cases. Conclusions This investigation indicates connections between acidification and changes in the lichen flora. The comparison of pH data from 1949-1970 and 1984-85, and the measurements of the air pollution show the occurrence of acidification in the region. Almost all species which do not prefer or tolerate acid substrates have disappeared from the locality, while almost all of the acid-tolerant species have remained. The increased trampling has affected only a very small part of the area. The spruc€ plantation probably had little influence on the lichen flora, since Degelius et al. found very few photophobous species. Therefore, it is highly probable that the acidification of the precipitation is responsible for their disappearance. The changes among the silicolous and tenicolous lichens on Romeleklint resernble previously known changes among corticolous ones. The tendency of this investigation is clear although a few species may have disappeared due to other factors than acidification. Lecanara muralis has remained at the locality although it prefers high pH values. An explanation may be that it grows in places which are occasionally manured by birds. Parmelia pulla, earlier stated to be abundant, has vanished. The species occurin the pH interval4.1-7.0 (-7.5), but it is also favoured by bird manuring. Perhaps the sensitivity to acidification is greater than that indicated by Wirth, if no fertilization oeurs. A retreat of the species has also been obserued in Stenshwud N. P., southeast SkAne (Ekman 1989). Porina chloroticaand Lecidella scabramay have disappeared due to the somewhat increased insolation when the spruce forest'was cut. Three Peltigeraspecies have also vanished, of which at least P. aninaand P- plydac'tyta were not sparse. This can also be due to the environmental changes towards the somewhat drier and more exposed conditions. Atthough they are tairlycapable of enduring desiccation (MacFarlane & Kershaw 1977, 1980), such drier conditions can strike very hard on local ecotypes, even if the species on the whole have a wide ecological amplitude. However, the acidification is another possible reason for the retreat of the Peltigera species. They demand a high substrate pH (see Table 3), and nitrogen fixation is known to be negatively influenced by low pH, especially in combination with high concentration of SO, (Heillgren & Huss 1975). A retreat of the Peltigera species has also been observed
Page 1 and 2: I, hh rje, r b Vo[- z rrn, y oktolr
Page 3 and 4: OveAlmbornTS6r ove och jag triiffad
Page 5 and 6: 125 Graphis Scripta 22125-127, 1989
Page 7 and 8: 127 previously reported). It was la
Page 9 and 10: 129 chromatography (fLC; Culberson
Page 11 and 12: . 1__--1 I I t \ t f 0 ( t oo qa tt
Page 13 and 14: 133 Huovinen, K., Ahti, T. 6. stenr
Page 15 and 16: Betriiffande avgrd.nsningsproblem h
Page 17 and 18: 137 Mycket talar emellertid ftir at
Page 19 and 20: 139 alpina. Bresinsky & Stangl (197
Page 21 and 22: 141 hopefully stabilized the nomenc
Page 23 and 24: Literature 143 Acharius, E. 1810: L
Page 25 and 26: 145 and threatened by modern forest
Page 27 and 28: 147 bryophytes. Sorkapp Land. rare.
Page 29: 149 The lichen flora on the peak of
Page 33 and 34: L. insularis L. lapicida L. orosthe
Page 35 and 36: Beferences 155 Arup, U. & Ekman, S.
Page 37 and 38: 157 snabbt och var Ig48 uppe i unge
Page 39 and 40: afien ej {terfunnen nyfynd Figur 4.
Page 41 and 42: Graphis ScriPta 2: 161, 1989. 161 G
Page 43 and 44: n.11610, pe Fraxinus excelsior. Vii
Page 45 and 46: 165 Museum j-n Giiteborg (Naturhist
Page 47 and 48: 167 Lamb, I. M- 1977 z A' conspectu
Page 49 and 50: I ov , , . Qaloplaca brattiae belon
Page 51 and 52: 171 The species is for the present
Page 53 and 54: 173 forest which appeared to the ve
Page 55 and 56: Graphis Scripta 2: 175, 1 989 175 C

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