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
28 Natura Somogyiensis The changes of orchid population size have been studied for a long time in Europe (e.g. the historical records of Himantoglossum hircinum in British Isles have been dated back almost 300 years, Good 1936). Their rarity and conspicuous inflorescence might contribute notably to this fact. Recently (ca. in the last 60-70 years) the investigations have already been tended not only to detect the occurrences and to estimate rough abundances (many, frequent, few etc.) but also to study detailed the temporal and spatial variability of population size, demographic traits, flowering frequency, life-cycle, etc. in order to get new knowledge of orchids which facilitate the more effective conservation and management (Willems J. H. and Melser 1998, WotavovA et al. 2004). In cases of orchids different kinds of methods were applied for observations. There are more complicated, time-consuming procedures when permanent quadrats, individual marks have been used, and in such a way the population sizes of orchids can be estimated more exactly. Another, more simple and easily practicable method is to follow the population dynamics counting the flowering individuals in a given site. Kull (2002) summarized the researches of the European north temperate orchids collecting data from 67 species studied at least for three years. In 40% of cited references only flowering individuals were studied. The lengths of the monitoring periods of different orchid species are varied from some years to more than ten years in Europe. The advantage of the long-term investigations is that a more reliable picture can get on the dynamics of populations depending from the environment (including for example the transitions of stages, survival possibility etc.). Among the numerous studies it is remarkable Tamm and his colleagues’observations (Tamm 1972, Inghe and Tamm 1988) who followed the survival and flowering frequency of four orchid species in permanent quadrats nearly for five decades in Sweden. Long-term demographic studies of two orchid species (Orchis morio and Herminium monorchis) concentrated mainly on the flowering behaviour affected by the climatic factors influencing the flowering processes (Wells et al. 1998). The demographic traits of Orchis simia were analysed over 18 years to find out the longterm survival strategy of an isolated orchid population by Willems and Bik (1991). The variation in population size of Orchis morio were assessed by the dynamics of flowering spikes over a 26 year period using unfertilized plots in a fertilizer experiment in Britain (Gilmann and Dodd 1998). In spite of many investigations, there is no general explanation for the yearly change of the flowering intensity. In the case of many orchid populations there have been successful explorations of the environmental effects which influenced the number of flowering individuals, the fruit-set formation (e.g. weather conditions: Wells 1981, Inghe and Tamm 1988, Wells and Cox 1989, Willems and Bik 1991, Carey 1999, Pfeifer et al. 2006a,b; herbivores: Wells and Cox 1991, Kindlmann 1999, Kindlmann and Balounová 1999). Among the recent Himantoglossum species H. hircinum is the best known. It was mentioned several times from many countries over centuries ((e.g. in the British Isles since 1641) (Good 1936). In Germany there is a valley (Leutra valley near Jena, Thuringia) where the flowering and vegetative individuals of H. hircinum have been monitored since 1878. The exact number of plants found between 1976 and 2001 was 13,687 (Heinrich 2000, Pfeifer et al. 2006a). H. hircinum has large distribution area, and almost every European speciemens was considered as H. hircinum until 1978, when Baumann described H. adriaticum from the Istrian Peninsula (Baumann 1978). The distribution area of the H. adriaticum is much smaller, than that of H. hircinum, but it is not limited to the region of the Adriatic Sea as the name would suggest. It also appears in Italy, Slovenia, Croatia, Austria, Hungary, in Slovakia up to Moravia and in Bohemia (near Ketkovice) (Rybka et al. 2005, Vukovic and Nikolic 2006).
