Dudov. Phytogeographical pattern of the Baikal-Dzhugdzhurian alpine flora. In: The East Asian Flora: and its role in the formation of the world’s vegetation

Phytogeographical pattern of the Baikal-Dzhugdzhurian alpine flora

Sergey DUDOV
Lomonosov Moscow State University, Moscow, Russia

The Baikal-Dzhugdzhurian province (Sochava 1962), includes the Baikal and Stanovoe Uplands, Stanovoy Range and ranges of Dzhugdzhur-Stanovoy orogen (Tokinskiy Stanovik, Dzhugdzhur, Pribrezhniy, etc.) and stretches for more than 1600 km inland from the sea of Okhotsk. According to several floristic studies the concerned territory is an important migration route for many vascular plant species and their complexes during Quarternary period climatic changes. Add to this, a mixture of different florogenetic alpine species complexes takes place, with continental eastern-Siberian, Beringian and southern-Siberian complexes among them. The Baikal-Dzhugdzhurian province can be considered as a one whole phytochorion due to the presence of a number of endemic species (Salix divaricata subsp. kalarica, Saussurea poljakovii, Claytonia udocanica, Taraxacum mujense, Saxifraga algisii, S. svetlanae, S. staminosa, Calamagrostis kalarica) and an endemic monotypic genus Borodinia. The study aims to specify the spatial differentiation frontiers of the Baikal-Dzhugdzhurian province alpine species. The following goals are: to compile the territory alpine flora data base, to evaluate the role of abiotic environmental factors in the alpine flora differentiation process and to develop a regionalization scheme. A Baikal-Dzhugdzhurian province alpine flora database was compiledusing reported data from herbarium material and own field material, collected within Dzhugdzhur, Geran and Tukuringra mountain ranges. It includes more than 840 plant species from above the tree line. This number includes 550 distinct alpine species and almost 300 mountain and additional species, which penetrate from lower altitudinal belts. As a result the territory is divided into 16 regions corresponding with the main mountain ranges of Baikal-Dzhugdzhurian province, floristic information about which is available. A phytogeographical regionalization scheme including four major alpine floristic regions was compiled using data from published regional floras, remote sensing, digital elevation and, climatic and geologic data.