【目的】 研究绿洲防护林体系的小气候效应,为绿洲防护林体系的长期经营与健康发展提供科学数据。【方法】 对乌兰布和沙漠绿洲防护林内、外2个气象站36 a(1983—2018年)连续监测的气象数据进行了统计分析,研究了2个站点的大气温度、地表温度、相对湿度、降水量、蒸发量,以及风速的年、季和月变化特征,分析了绿洲防护林内、外小气候的差异并探讨了产生差异的原因。【结果】 ①绿洲防护林内、外的大气温度、地表温度和降水量年际变化特征总体呈上升趋势,相对湿度、蒸发量和风速总体呈下降趋势,绿洲防护林体系使大气温度降低0.2~1.6 ℃,地表温度降低0.10~5.49 ℃,相对湿度增加0.5%~18.6%,降水量增加0.5~100.7 mm,蒸发量降低18.4~1 282.8 mm,风速减小0.45~1.98 m/s;②绿洲防护林内、外的每10 a的气温变化倾向率分别为0.27、0.32 ℃,地温变化倾向率分别为0.28、0.36 ℃,降水量变化倾向率分别为1.8、2.5 mm,相对湿度变化倾向率分别为-0.2%、-1.3%,蒸发量变化倾向率分别为-42.5、-78.4 mm,风速变化倾向率分别为-0.1、-0.2 m/s;③绿洲防护林内和林外大气温度、地表温度、相对湿度、降水量和蒸发量的年内变化规律均为先增加后降低,为单峰曲线,而风速的年内变化曲线为双峰曲线;④绿洲防护林内、外各环境因子具有明显的季节差异,春、夏、秋、冬四季大气温度、地表温度和蒸发量增长率均为林外高于林内;四季相对湿度均为林内高于林外,风速则相反;降水量春、夏季林内高于林外,秋、冬季为林内低于林外。【结论】 绿洲防护林体系具有降低气温和地温、减少蒸发、降低风速、增加空气相对湿度和降水等生态功能,防护林及其内农作物生长季节尤为明显,这对于提高作物产量起着积极作用,进而改良土壤,并对维持绿洲可持续发展起着重要作用。

【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.