Characteristics ofJuglans regiaL sap flow and its response to reference evapotranspiration on different time scales in rocky mountains of North China

Abstract

Walnut (Juglans regia L.) is an important economic tree species in rocky mountain of North China, which plays a key role in adjusting agricultural structure and promoting farmers忆 economic income. As a kind of hygrophilous tree species, irrigation is the main measure for the walnut water management in the region located in semi鄄arid zone with limited water resource. So it is necessary to accurately evaluate water consumption of walnut trees during the growing seasons to enhance water use efficiency. The main purpose of this paper is to observe and analyze the individual walnut water consumption and its response to meteorological factors during the growing seasons. Sap flow of walnut trees was measured by thermal dissipation probe (TDP) method and meteorological factors, reference crop evapotranspiration were acquired by automatic weather station and local astronomy data. The study measured, analyzed diurnal and monthly sap flow characteristics of individual trees of Juglans regia L. and the relationship with meteorological factors, reference crop