ANALYSIS OF DWARF MISTLETOE ARCEUTHOBIUM OXYCEDRI (DC.) M. BIEB. AND ITS PRINCIPAL HOST EASTERN PRICKLY JUNIPER JUNIPERUS DELTOIDES R. P. ADAMS DISTRIBUTION IN CRIMEA USING GIS TECHOLOGIES

The current study highlights the distribution pattern of juniper dwarf mistletoe (Arceuthobium oxycedri), a semi-parasite of the Eastern prickly juniper (Juniperus deltoides), in Crimea. A. oxycedri has considerably narrower range in Crimea as compared to its principal host and its ubiquitous distribution is rather sporadic. Nature observations characterize A. oxycedri as a thermophilic and mezo-хerophytic species confined to the low-mountain terrains with mild sub-Mediterranean climate. Significant sites of permanent infection have been discovered at the Crimean coast and in the warmest southwestern part of the Crimean Mountains to the south from the Belbek River valley. Greek juniper (J. excelsa) is a codominant species growing side by side with J. deltoids in the majority of localities examined that have the high infection rate. Generally, J. excelsa is an insusceptible species in relation to the parasite; nevertheless, it is affected by A. oxycedri at several sites. Birds feeding habit to consume J. excelsa and J. deltoides fleshy berry-like cones helps to maintain the high infection rate and to disseminate mistletoe seeds at the distance of approximately 4 km. Modeling ecological niche and creating maps of potential range of the parasite and its principal host using MaxEnt 3.3.3k software have demonstrated that A. oxycedri distribution in Crimea at present may be wider than it has been currently observed. It is noteworthy that while modeling such bioclimatic indicators as the minimum winter temperatures and the elevation above sea level were irrelevant for establishing the distribution range of the parasite. Presumably the limited distribution of A. oxycedri can be attributed to the history of forming J. deltoides range in the late Pleistocene – Holocene, alongside with a low speed of the parasite dissemination from Quaternary refugia in the southernmost part of the Crimean Peninsula