B. Papp szerk.: Studia Botanica Hungarica 37. 2006 (Budapest, 2006)

Dobolyi, Konstantin: Study of the population dynamics of Linum dolomiticum Borbás (Linaceae)

Average seed number per fruit: 4.95. Since maximum seed number per fruit is ten, fertility rate is 0.495 seed/fruit. Total seed production: 74,600 seeds/year (± 10%). Demographic data of the sample area and data of change of population are given in the Table 1. The number of individuals within the sample area has slightly decreased over the four years of the investigation. Since no sign of degradation was detected in the area, this can be explained by the extreme dry and hot weather during the study. However, the mapping of distribution has verified that the number of individuals has increased in several parts of the population. The total number of individuals in the whole population seems to be stable (DOBOLYI 2004). The strikingly high ratio (circa 20%) of the new and disappeared individuals is an indication of intensive dynamic processes within the population of Linum dolomiticum. This reproductive dynamism is regarded as a positive sign of a healthy and strong ability of survival. Large empty areas surrounding the Linum dolomiticum patches of high density offer the possibility of future colonisation. After analysing the maps of the sample area made in 2001, 2003 and 2005 it has become clear that a certain portion of the "extinct" individuals in fact has not died: some of those present in 2001 but absent in 2003 have re-appeared in 2005. These "old-new" individuals had to survive in the ground for two years without sprouting. The size of these individuals was found between 5 and 10 cm, which prove that they are not seedlings. This observation revealed that Linum dolomiticum can remain in dormant state for several years. About 10-20% of the new individuals were found to be seedlings (of 1-2 cm). At this stage of the research it is concluded that the estimated population size with regard to the considerable seed production and the high reproductive ability appears to be large enough for the long term survival of this species, however, the effective population size has to be determined during future monitoring studies. Acknowledgement - This work was supported by the EU LIFE-Nature project entitled Restoration of Pannonian forests and grasslands on the Szénás Hills (LIFE 03 NAT/H/000167). REFERENCES BAGI, I. (2006): A Botrychium virginianum (L.) Sw. kunfehértói állományának populációstruktúrája és dinamikája. (Population structure and dynamics of rattlesnake fern (Botrychium virginianum (L.) Sw.) in Kunfchértó, Hungary.) - Kitaibelia 11(1): 6.