Vegetation of accumulative flood terrace: phytocenetic characteristics and bioproductivity (Western Transbaikalie)

The characteristics of the vegetation in accumulative flood terrace in the lower reaches of the rivers of the dry steppe zone of Transbaikalia are given. It is established that the flora of floodplain marshy communities is represented by 21 families of 55 genera and 77 plant species. The share of the species composition of top 5 families (Poaceae, Fаbасеае, Cyperaceae, Asteraceae, Rosaceae) accounts for 59.7% of the total number of species, that is conform to the soil-climatic conditions. A large number of single-species families (7) and genera (10) is the indicator of extreme conditions for vegetation. Hydro-mesophytes and eumesophytes, as well as species of long and short rhizomatous plants are dominated. Marshy meadows productivity is average - 3686-7380 g/m2 per year. The ratio of aboveground and underground phytomass as an indicator of environmental conditions is relatively constant 1:9,9 - 1:12,5.