Savaria - A Vas Megyei Múzeumok értesítője 17-18. (1983-1984) (Szombathely, 1989)

Természettudomány - Kiss Tamás: Autökológia és indikáció. Kritikai elemzés a zuzmók indikátor szerepéről

In the analysis and the interpretation of the dynamical processes we can find connections with Clements' ideas. The research of the lichen communities is on the basis of Braun-Blanquet's system even now days. Although Gams (1932) has already showed the subjective characteristics of Braun-Blanquet's system, but his remarks, as well as his new life-form system, remained without any attention at that time. In consequence of these facts we have to establish that there were no suitable methods at the beginning of the indicational researches. There are few coenological observations from the cities or their surroundings (Mattick 1937, Felföldy 1942, Laundon 1967, Gilbert 1970, Deruelle 1978, 1979 etc.). Therefore the period of the autecology has come. A very important aspect of a city environment is its polluted air. The presence of sulphur dioxide, nitrogen oxides, exhaust etc. in the atmosphere bring about the series of complicated processes. Therefore the exact indication of the air pollution is a very difficult task. The so-called "pollution hypothesis" and "drought hypothesis" are the results of the simplification of the problems, or simply inaccurate conclusions which came to the well-known inexact question ; "Is it dryness or is it pollution of the air which causes the impoverishment of lichens in cities and industrial environments?" Thinking about the complexity of meteorological processes taking place in the atmosphere {Mészáros 1977), these hypotheses are can not be accepted. Both hypotheses emphasize an ecological factor which results in neglection of other ones. Although the harmful effects of the sulphur dioxide were proved in the laboratory (e.g. Leblanc and Rao 1966 etc.) but we have very few exact evidences about the behaviour or responses of the lichen thalli and communities to the poisonous gases living in changing urban environments {Seaward 1976a, 1980, Will-Wolf №0, Lawrey 1981, Kiss 1983). The studies of Seaward {1976a, 1980, 1981) and the researches of Henderson-Sellers and Seaward (1979) carry important results first of all in connection with the lichen reinvasion in ameliorating environments. As Henderson-Sellers and Seaward {1919) have written; "We consider that these results underline the fact that sulphur dioxide level alone is no longer the major factor affecting lichen colonisation- and, ipso facto, its distribution - within the West Yorkshire conurbation and many other urban areas." They have also attracted the attention to the importance of the effects of other environmental parameters : "Any successful use of bioindicators must depent upon the rigorous definition of the scales monitored by the organism and perhaps even more importantly, a complete analysis of all the environmental parameters which affect the organism's propagation, establishment and subsequent growth." Further complications come from the possible synergistic effects of the pollutants, and the pollutants may act synergistically with the heavy metals, too {Seaward-Goyal and Bylinska 1978). The so-called "vitality scales" which reflect to the degree of decay of the lichen thalli are also rather subjective, - {Steubig-Kirschbaum and Gwinner 1976, Kirschbaum 1978 etc.) - for example in the determination of the colour of the thalli. The change of the colour of the thalli may happen in non-polluted areas, too {Jahns 1973, Kiss 1981). Another useful method of the researches is the transplantation. Lichen thalli were transplanted from an unpolluted area to a polluted one to provide evidence of injury caused by pollution. The scientists observed that the transplanted thalli were seriously damaged by the effect of S0

2 or HF {Rao-Leblanc 1966, Gilbert 1968, Schönbeck 1969 etc.). We have to recognize that the transplantation of a thalli from an unpolluted area to a polluted one - or vice versa - is a typical autecological method. The transplanted thalli are taken out from a community, from a time-space pattern, 24