Water relations in the relict savanna edificators of South Tadzhikistan.
Water relations in the soil-maintaining species Imperata cylindrica and Erianthus ravennae of unique vegetation growing in the arid subtropical zone of South Tadzhikistan were studied. Data are given on transpiration rate, leaf water content, water retention, osmotic pressure, midday and residual water deficits, and the rate of water use. High groundwater levels and efficient use of water enabled both species to maintain their water economy. Water relations parameters did not reach critical values even at the highest summer temperatures. Because of this, both plant species produced stable, highly productive swards in the floodplain ecosystems of the Central Asian arid zone.