Abstract
Recently, we are studying on the relation between the vegetation and its environment in an arid area in northwest of China. In this paper, we reported some results on the measurement of air temperature and relative humidity which were collected in August and September from different areas of Xinjiang Uygur Autonomous Region and Gansu Province in China. Values of moisture per dry air were read out as another humidity indicator by the psychrometric chart based on the relationship between temperature and relative humidity. In comparison, the diurnal ranges of temperature in the desert of Xiaotang, especially near the ground, are larger than those in the oasis of Aksu. Moisture in the oasis is generally slightly higher than in the desert. It is thought that conditions in areas without vegetation show more clear diurnal variation of air temperature than those in oasis. Differences on temperature and humidity were not apparent from areas with sparse stand of Populus to areas with sparse Tamarix scrub on a river side, and as the remaining Populus stands became fragmentary and sparse in the deseart areas. In some cases, however, values of temperature were almost lower, and values of air moisture were higher in Populus stands than outside the stands. The tendency than desert areas were more hot and dry than oases was clear based on the measurements done intermittently for one day trip from Aksu to Korla. As big cities produce "heat-island", oases produce "moist-island" in the arid region because they include wide and well-cultivated areas.
