民勤绿洲-荒漠过渡带典型固沙植物生殖物候对气候变化的响应

通过对民勤绿洲-荒漠过渡带典型固沙植物多枝柽柳(Tamarix ramosissima)、梭梭(Haloxylon ammodendron)、白刺(Nitraria tangutorum)1974-2009年开花及结实物候的观测,结合同步观测的气象资料,分析了3种植物生殖物候特征对气候变化的响应规律。结果表明:(1)研究区年平均气温、年平均空气相对湿度呈增加趋势; 年降雨量波动,变幅不大; 20世纪90年代以来蒸发量呈显著下降趋势。(2)3种植物始花期提前,花期延长; 3种植物结实始期先延迟后缩短,结实期延长; (3)3种植物生殖物候与年降雨量、气温、空气相对湿度及前期累计降雨量、累计平均气温、累计空气相对湿度之间的相关性不一致; (4)3种植物始花期与前期累计降雨量、累计平均气温、累计空气相对湿度的相关性总体上表现为大于年降雨量、年均气温、年均空气相对湿度的相关性; 除空气平均相对湿度对结实始期影响大于前期累计降雨量、累计平均气温和累计空气相对湿度外,其他与开花物候相似,表明植物开花物候和结实物候与前期气象因子有着密切的关系,尤其是物候发生前期累计气象指标。

Response of Reproductive Phenology of Typical Sand-fixing Plants to Climate Change in the Oasis-desert Transitional Zone in Minqin,Gansu, China

Phenological data of three typical sand fixing plants (Nitraria tangutorum, Tamarix ramosissima and Haloxylon ammodendron) in the transitional zone between the Minqin Oasis and desert, and the corresponding meteorological data were both collected from the Minqin Desert Control Experimental Station in 1974-2009, and reproductive phenology characteristics of three species to climate change was analyzed. The results showed that: (1) Annual average temperatures and annual humidity showed an increasing trend, annual average precipitation was fluctuated and varied in a small range annually, and annual evaporation has marked drop trends since 1990s. (2)Flowering period of the three species showed advance with the increasing of time, duration of flowering showed an increasing trend, but fruiting period of three species showed advance with the increasing of time, duration of flowering showed an increasing trend. (3) Reproductive phenology of the three species is not identical with annual rainfall, annual average temperatures, annual average humidity and accumulated temperature, accumulated temperature, accumulated humidity from the preceding of reproductive phenology. (4) Relation of flowering period with accumulated temperature, accumulated temperature, accumulated humidity is higher than annual rainfall, annual average temperatures, annual average humidity. Relation of fruiting period showed the same character with flowering period except accumulated humidity. Flowering period and fruiting period have a close relationship with meteorogical facters of phenological earlier, especially accumulated meteorogical index.