Ubugunov V.L., Merkusheva M.G. Lead in soil-plant system of steppe communities of Ivolginsk Hollow (Western Transbaikalian) // Ecology of Siberia the Far East and the Arctic / Int. conf. (Sept. 5-8). – Tomsk, 2001. – P.290.

 

LEAD IN SOIL - PLANT SYSTEM OF STEPPE COMMUNITIES OF IVOLGINSK HOLLOW (WESTERN TRANSBAIKALIAN)

Ubugunov V.L., Merkusheva M.G.

Institute Of General And Experimental Biology SB RAN,

670047, Ulan-Ude, Sakhyanova st., 6, E-mail: ioeb@bsc.buryatia.ru,

Ph.: (301-2) 335065, fax: (301-2) 330134

 

The lead, alongside with macro- and microelements, is drawn into chemical elements circulation in soil - plant system. The level of Pb accumulation in overground phytomass is one of the important criteria of sward fodder value estimation in regions, where animal industries is advanced.

In the message results of study of lead contents, accumulation and distribution in soil – root mass – overground phytomass system of steppe (лапчатково-мелкозлакового, люцерново-ковыльного and ковыльно-разнотравного) communities, growing on chestnut and meadow-chestnut soils, are showed.

The Pb contents in chestnut soil varied in limits 2.0-5.4 and in meadow-chestnut soil – 6.4-14.3 mg/kgs. In chestnut soil structure is marked insignificant accumulation of the element in the top part, in meadow-chestnut - in bottom. Pb distribution in the soil structure correlated with the contents of physical clay (r = 0.63).

Root mass of steppe communities is equaled to 91-97 % of total phytomass.  Lead content in root mass is equaled to 6.6-10.2 mg/kgs, in oveground phytomass – 1.2-5.2 мг/kg or 1.8-5.0 % from total stocks.

Accumulation coefficient, that showed root system protective functions, tantamount to 1.7-2.9. It’s established, that plant-dominants accumulation specificity of lead is species one. So, greatest quantity of the element is accumulated by лапчатка вильчатая, гетеропаппус tartar and полынь метельчатая (4.8-6.0 mg/kgs), least - by ковыль Крылова and мятлик оттянутый (1.2-1.6 mg/kgs).

Is thus established, that steppe soils of Ivolginsk hollow didn’t contain toxic  concentration of Pb. Overground phytomass of steppe communities didn’t accumulate superfluous and exceeding limit admissible concentration of the element. Major factors of lead accumulation and distribution are in soils the contents of physical clay, in plants - barrier function of root mass – overground phytomass system and species specificity of steppe communities.