A study on transpiration characteristics of main shrubs Caragana intermedia,Salix psammophyla,Hedysarum mongolicum,Hippophae rhamnoides in zhungeer hill region

The Zhungeer hill region is located in the west part of the Ordos Plateau,Inner Mongolia.It is a key region for soil erosion control and eco-environment reclaimation.The transpiration characteristics of main shrubs Caragana intermedia, Salix psammophyla,Hedysarum mongolicum, Hippophae rhamnoides ssp.sinensis in Zhungeer hill region,were measured under natural conditions by using a portable LI-1600 steady state porometer in the late August,2001.The results indicated that Hippophae rhamnoides ssp.sinensis had no noon expression with single-peak pattern.From (12:00) to 16:00,the transpiration rate all kept higher value.The diurnal changes of transpiration rates of other three shrubs were all double-peak curves.The order of diurnal transpiration rate of the four shrubs was Hedysarum mongolicum Hippophae rhamnoides ssp. sinensis Salix psammophyla Caragana intermedia.Under the situation of continuous dry in recent three years, the diurnal water consumption of individual plant of Caragana intermedia, Salix psammophyla, Hedysarum mongolicum, Hippophae rhamnoides ssp. sinensis in mean size through transpiration was 887.69 g,3739.30 g,1907.57 g and 1169.57 g.The results provide the basic data for soil erosion control,ecosystem water balance, and ecosystem reclaimation in the farming-pastoral zone of northwest China.