Iris Rabbitear Kasatik (Iris) laevigata Fischer et Meyer – distribution features on the north-western border of the area

Abstract

As a result of special work, it was revealed that the Iris Rabbitear Kasatik (Iris) laevigata Fischer et Meyer is a rare species of the Irkutsk region, the Republic of Buryatia and the Transbaikal Krai. It is shown that until recently, the features of its distribution in the northwestern edge of its area were unknown. Our special long-term research has allowed us to identify it in many parts of this region. It is shown that all his finds are limited to the occurrence of small curtains of this species (2-10 flowering plants, rarely up to 20 and only in two cases 50-70 flowering stems). It has been established that this species is most common on the rivers of the Republic of Buryatia – Upper Angara and Kichera. The most typical stations of the species have been identified - very well-insulated open parts of grass-sedge swamps with separate lakes. It is shown that the main limiting factor for it is the lack of heat at the northwestern border of its area. Here, its distribution is limited by the mountain floodplain water regime. Summer floods coming from the mountains and reaching the strength of large and even catastrophic floods carry very cold waters, strongly depressing the vegetation of aquatic vegetables. It is proved that the conservation of this species can only be ensured by creating a network of differently ranked specially protected natural territories. For species with a local distribution of small parts suitable for their habitat, the organization of Natural Monuments at the republican and federal levels is the most promising.