Towards a definition of the Dahurian flora

Konstantin BAIKOV
Institute of Soil Science and Agrochemistry SB RAS, Novosibirsk, Russia

Differing points of view on the status and division of the Dahurian flora and its boundaries are considered in detail. The Dahurian flora is represented as an association of three florogenetic complexes: meadow-forest Mandshurian, mountain- forest East Siberian and dry steppe North Mongolian. The determination of external boundaries of the Dahurian flora depends on a choice of the concrete complex as a floristic kernel (dominant). The concept of the Hingan-Yablonovyi- Hentei cascade phenomenon through the transfer of damp Pacific Ocean air midland, may also influence physico-geographical limits of the Dahurian flora. As a result, Dahuria as naturally occuring florogenetic entity is therefore placed in a pool of northern (left) inflows of the Upper Amur river. The Amurian flora is thus florogenetic, presenting transitional features from the boreal megaflora of the East Siberian type to warm-temperate megaflora of the East Asian type. The florogenetic profile of Dahuria includes three floristic groups of a steppe element: forest-steppe, steppe and mountain-steppe. Each of these in different areas of the Dahurian flora consists of 80 to 140 species. Here the focus is on the area of shrubs (Ulmus macrocarpa, Securinega suffruticosa, Lespedeza spp., Rhamnus, Cotoneaster, Fraxinus, Viburnum, Spiraea, Rosa and Armeniaca sibirica) and some perennial herbs (Euphorbia fisheriana, Pardanthopsis dichotoma, Paeonia lactiflora, Dictamnus dasycarpus etc.). The main cause of divergence between the Dahurian and Mandshurian flora is the Big Hingan Mountains – the great boundary in the Hingan-Yablonovyi-Hentei cascade with a defined rain shadow that reflects a sharp boundary within the gradient of the Pacific Ocean moisture transfer. A more detailed definition of internal elements of the Dahurian flora will require the application of the basin principle and a hierarchical description of land ecosystems.

© 2012 Organizing Committee