Research on Plant Transpiration Characteristics of Hunshandake Sand

This paper measured the transpiration rate (Tr) of main natural species and environmental factors by Li-1600 steady porometer at the different seasons on the Hunshandake sand. The result indicated the diurnal change trends of transpiration rate of the five plants (Ulmus pumila , Salix gordeievii,Salix kochiana?Betula gmelinii,Aneurolepidium chinense ) is single-range curve, whereas the other species (Polygonum divaricatum,Ries diacantha) transpiration rate diurnal course are bi-range curve. The transpiration rate of same plant is different in different soil water content of different plot. The changes of mean transpiration rate of these species are distinct in different seasons. The transpiration rate is highest in July, and lowest in June. The average transpiration rate of S. gordeievii is lowest in all species. The regression analysis suggests that the most dominant factor is photic intensity; the other factors are air relative humid and air temperature for every plant. The relationship between transpiration rate and environment factors are liner, the transpiration rate model can be expressed by the equation Tr=a+bRH+cT+dQ.