Acta Botanica Croatica, Vol. 47 No. 1, 1988.
Izvorni znanstveni članak
The Importance of I. Horvat’s Unpublished Text on the Historical Development of the Vegetation in South-Eastern Europe
Nikola Pantić
; Srbija
Vanda Kochansky-Devidé
; Hrvatska
Zvonimir Devidé
; Hrvatska
Sažetak
During the Tertiary and Quartary the evolution of the continental vegetation of South-Eastern Europe depended on the changes of its environment, especially of the climate and the geodynamical events. This knowledge is the result of a synthesis of long time palaeobotanical investigations of the first author of this paper (Pantic 1954, 1956, 1967. 1986, 1987).
Thirty years ago Professor Ivo Horvat (1897—1963) came to similar ideas based on his fundamental research into taxonomy and vegetation as well as on parallel studies of plant associations and their migrations during the near geological past, considering especially the changes of the climate.
In the monograph by Horvat, Glavač and Ellenberg : »Vegetation of South-Eastern Europe«, however, the chapter of Horvat’s original manuscript: »The plant world of South-Eastern Europe as an expression of geological and historical vegetational events« was omitted. In this unpublished text (120 typewritten pages) there are many significant ideas, which should be pointed out, because they are — although they were not understood at the time when Horvat has wrote them
— now recognized as being correct and valid.
There are, in general, three important problems:
1. Horvat points out the exceptionality of the continental vegetation of South-Eastern Europe during the Tertiary. In the Central and Eastern Europe sensitive species disappeared much earlier than in the Balcans, where they survived owing to the protection of the mountain chains. The Pliocene sediments of the Balcans are in respect to climatic conditions much like those of the Miocene of Central Europe. In South- -Eastern Europe a retardation of the warm climate and vegetation occurred. Horvat was one of the first to realize this fact and to point out that one must — when investigating the development of a vegetation
— consider the fixed flora (repère flora), regardless of the index significance of several species. It is also necessary to consider the factor of palaeobiogeographical characteristics of a country.
2. Horvat bravely accepted Milanković’s theory of climate changes in the Antropogene, although at that time (untill 1963) most palaeoclimatologists did not agreee with Milanković’s concept until 1976, when his work was definitely accepted, especially since the Symposium »Milankovitch and Climate«. Columbia University, 1982 (Pan tie 1983a, 1983b).
His scientific intuition led Horvat to write (p. 41 of his manuscript) : »Acceptance of the movements of the earth’s poles according to Wegener and Koppen can explain the glacial periods, but not the interglacial ones. For them an ingenious interpretation (Milanković 1941) can be found in periodical changes of insolation during the last 650 000 years. Milanković calculated the insolation of the northern hemisphere during the last 1 000 000 years and was able to prove that periodical changes of some astronomical magnitudes, namely the obliquity of the ecliptic, the excentricity of the earth’s orbit and the precession of the vernal equinoxes point cause the periodical decrease or increase in the summer temperature«.
3. In Horvat’s interpretation the development of the Tertiary-Quartary vegetation is successfully connected with the recent situation of the vegetation in South-Eastern Europe. Original and exhaustive phytocoenological explanations have been given by Horvat as an expression of geological and historico-vegetational processes.
A long period of research will be needed before all vegetational changes during the Tertiary and Athropogene in South-Eastern Europe can be explained. But even then it will be obvious that Horvat’s unpublished text (Horvat 1963) represents a significant contribution to endeavours way how to approach and solve the significant palaeoclima- tological, palaeobotanical and phytogeographical problems.
Ključne riječi
Hrčak ID:
159452
URI
Datum izdavanja:
31.12.1988.
Posjeta: 1.130 *