关键词: 小气候效应, 气象因子, 沙漠绿洲, 防护林体系, 乌兰布和沙漠

Abstract:

【Objective】 The oasis in arid areas is a necessary element for economic prosperity and development, and climate factors play a vital role in maintaining the sustainable development of the oasis. Studying the microclimate effect of oasis shelter forests can provide scientific data for the long-term management and healthy development of oasis shelter forests. 【Method】 Inside and outside the oasis shelter forest system of the Ulan Buh Desert was used as the research object, and statistical analysis of 36 years (1983-2018) meteorological data continuously monitored by the two meteorological stations set on the grounds of both oasis shelter forest and desert-oasis ecotone in the Ulan Buh Desert was used. The interannual, annual and seasonal variations in air temperature, soil temperature, relative humidity, precipitation, evaporation, wind speed and the differences in microclimate inside and outside the oasis shelter forest system were analyzed, and the reasons for the observed differences were discussed.【Result】 ① The interannual variation characteristics of air temperature, soil temperature, and precipitation within internal and external shelterbelts showed an increasing trend, but the interannual variation characteristics of relative humidity, evaporation and wind speed showed a decreasing trend. The oasis shelterbelt could reduce the air temperature by 0.2-1.6 ℃ and the soil temperature by 0.10-5.49 ℃; it increased the humidity by 0.5%-18.6% and precipitation by 0.5-100.7 mm; the evaporation decreased by 18.4-1 282.8 mm, and the wind speed decreased by 0.45-1.98 m/s. ② The change trend every 10 years in temperature was 0.27, 0.32 ℃;land ground temperature was 0.28, 0.36 ℃;precipitation was 1.8, 2.5 mm; relative humidity was -0.2%, -1.3%;evaporation was -42.5, -78.4 mm; wind speed was -0.1, -0.2 m/s, respectively, within internal and external shelterbelts. ③The annual variation characteristics of air temperature, soil temperature, relative humidity, precipitation, evaporation within internal and external shelterbelts increased and then decreased; a single-peak curve was observed. The annual variation in wind speed was a double-peak curve. The air temperature, soil temperature, evaporation and wind speed of the internal shelterbelt were lower than those of the external shelterbelt, and the relative humidity and precipitation of the internal shelterbelt were higher than those of the external shelterbelt. ④ Meteorological factors of internal and external shelterbelts had seasonal differences. The growth rates of air temperature, soil temperature, and evaporation in spring, summer autumn and winter in the external shelterbelt were higher than those in the internal shelterbelt in four seasons. The relative humidity of the four seasons within the internal shelterbelt was higher than that of the external shelterbelt. The wind speed of the four seasons within the internal shelterbelt was lower than that of the external shelterbelt. The precipitation of the internal shelterbelt in the spring, summer, higher than that of the external shelterbelt, but were the opposite in autumn and winter. 【Conclusion】 The oasis shelter forest system has the ecological functions of reducing air temperature, soil temperature, evaporation and wind speed while increasing air relative humidity and precipitation. This function is observed in the shelter forest and its crop growing seasons. It also has a positive effect on crop yield, further improving the soil. The function of the oasis shelter forest system plays an essential role in maintaining the sustainable development of the oasis.

Key words: microclimate effect, meteorological factor, oasis, shelter forest system, Ulan Buh Desert