Measuring Transpiration of Undisturbed Tamarisk Shrubs

Abstract

A method was developed for rapid and direct measurement of rate of water vapor production of undistrubed plots of natural vegeta-tlon in the field. It is directly applicable to a primary and recurring question in watershed management research, "Would this land lose less water if the vegetational cover were altered?" Evapotranspiration (ET) of grass-tamarisk plots increased linearly but not proportioally with amount of tamraisk. Diurnal time-course of ET followed generally those of light intensity and humitity deficit On clear days ET for a midday period (10:00 AM to 2:30 PM) and for the night (8:30 PM to 5:30 AM) was 36% and 11% of 24 hr total.