近52 a长白山苔原带生长季气候变化特征

利用长白山苔原带天池站1959-2010年6-9月气象数据，进行生长季气候变化分析。采用距平值、小波分析、Mann Kendall检验相结合的方法，进行温度、降水周期性变化与突变点的检验；采用线性倾向估计法，分析未来气候变化的趋势；并通过气候变化指数，反映其气候变化情况。结果显示：52 a来，长白山苔原带生长季经历了暖湿-冷干-暖湿-冷干-冷湿-冷干-暖干几个主要阶段，温度变化周期为5～10 a，降水变化周期为5 a和20 a.。温度变化的突变年份发生在1998年，降水变化较之温度变化复杂，其存在多个突变年份；各气象要素的变化趋势大都表现为显著的升高，其中温度的变化最为明显，风速、日照时数的变化甚微；霜冻日数与冰点日数均显著减少，极端温度大多出现在21世纪；伴随着>0.1 mm降雨日数的显著减小，长白山苔原带降水强度不断增加；与植物生长相关的生长季≥0 ℃积温、≥3 ℃积温和≥5 ℃积温在52 a间呈显著增加趋势，积温的增加将会对生长季的延长及植物生长起到显著的促进作用。

Study on Climate Change in Alpine Tundra of the Changbai Mountain in Growing Season in Recent 52 Years

Research on climate change in alpine region can provide a valid reference for studying the dynamic change of vegetation in alpine zone. In this paper, climate change in the alpine tundra of the Changbai Mountain was analyzed using the meteorological data observed by Tianchi Meteorological Station in growing season during the period of 1959-2010. Wavelet analysis and Mann Kendall test were used to reveal the periodic variations and anomalies of temperature and precipitation. Trend of climate change was analyzed using the linear methods. Six indices were selected to characterize climate change. Results showed that 7 main stages of climate change occurred in the alpine tundra in growing season, including the warm rainy, cold arid, warm rainy, cold arid, cold rainy, cold arid and warm arid periods in recent 52 years. There were the 5-10 year periodicities of temperature change, but the 5 year and 20 year ones of precipitation change. An abrupt temperature change occurred in 1998, and many abrupt precipitation changes occurred as well in a complex pattern. Temperature was in a significant increase trend, which suggested that it would be warmer and rainier in alpine tundra of the Changbai Mountain in the future. Numbers of FD (frost day) and ID (icing day) were decreased in recent 52 years. Extreme temperatures, such as Tmax and Tmin, occurred usually in the 21st century. The days of precipitation >0.1 mm were significant decreased, and SDII (Simple precipitation intensity index) was in an increased trend. Accumulated temperatures ≥0 ℃, ≥3 ℃ and ≥5 ℃ were significant increased in growing season, which played an important role in the growing season extension and tundra plant growth.