Ábrahám Levente (szerk.): Válogatott tanulmányok IV. - Natura Somogyiensis 15. / Miscellanea 4. (Kaposvár, 2009)
Bódis Judit - Molnár Edit: Himantoglossum adriaticum H. Baumann populáció hosszú távú monitorozása a Keszthelyi-hegységben
Bódis J. & Molnár E.: Himantoglossum adriaticum 35 Discussion Number of flowering individuals Counting flowering plants at a given site can be used to estimate trends in population performance. Although it does not show population size or flowering percentage. During the 17-year monitoring period the number of flowering plants of H. adriaticum varied considerably between years (coefficient of variation 64.2). There were sevenfold difference in the number of flowering plants between the richest flowerful year and the poorest one. It was only three years when more than 50 individuals were able to flowering. From this point of view especially 1995 and 1996 proved to be very good years for H. adriaticum in the Keszthely Hills. The number of flowering H. adriaticum speciemens in this site is few comparing with that of H. hircinum in Germany or in England. Other European orchid species have also great temporal fluctuations in the number of flowering plants. According to the results of long-term monitoring of H. hircinum population in the Leutra Valley (in Germany) carried out since 1960, the number of flowering plants reached almost 300 in 1974 and 1975, in other years it remained under 100 individuals. There began a long-lasting rise in 1988, which was disturbed by intensive fluctuations and with an extremely high value in 1995, when there were nearly 1400 inflorescences. Although in the next year were only a few inflorescences, there were 900- 1000 flowering plants in 1997 and 1998 (Heinrich 2000). The number of the flowering individuals changed very similarly to another population in Thuringia, where was also a large increase in 1995 (Heinrich and Voelckel 1999). The number of flowering individuals has been observed in the two largest populations of H. hircinum in England for a long time. Both populations had a small peak around 1950 and then had very low numbers until the 1980s. Later an intensive increase was observed in the abundance of flowering individuals, which resulted in 250 and 6000(!) inflorescences in the two sites (Carey et al. 2002). In the comparisons of spatial and temporal variation of Orchis morio's flowering spikes in a 26-year meadow experiment Gilmann and Dodd (1998) established that the number of flowering orchids were varied to much higher degree from site to site than in time. In many cases of orchid species similar findings were published by Kull (2002) in his review. According to Kindlmann and Balounová’s study with Dactylorhiza majalis the irregular flowering pattern may be typical for sites with temporarily or steadily declining populations. Several environmental factors (e.g. unsuitable habitat, wrong management, unsuitable weather conditions) can contribute to the irregular flowering in a given site (Kindlmann and Balounová 1999). The only conclusion can be drawn from the intensive fluctuation of the flowering individuals is whether the environmental conditions were favourable for the reproduction or not (when there are many flowering individuals, such year is called a “good orchid year”). To follow the dynamics of the population, we cannot leave out of consideration that the fluctuations in the number of flowering plants counted is not a true indicator of population size because juvenile plants were not counted in the population and only a proportion of the adult plants flower each year (Carey et al. 2002). Number of flowers and fruits on the spike The number of flowers is a characteristic feature in the identification of the different Himantoglossum species. While H. hircinum is characterised by dense inflorescence with many (40-120) flowers, the H. adriaticum has a loose inflorescence with only 25-50 flowers (Baumann and KOnkele 1982, Buttler 1986, Adler et al. 1994).
