【摘要】 山地系统作为植被脆弱带及气候转换与变化的敏感区,能直观反映植被对全球环境变化的响应及适应过程。该文基于1982-2015年GIMMS NDVI 3g时间序列数据集,利用TIMESAT 3.3动态阈值法提取六盘山山地植被物候参数,结合气温、降水及光照数据集,利用最小二乘法趋势检验、偏相关分析等方法,研究六盘山山地植被物候分异规律及其对气候变化的响应。结果表明:1)六盘山山地植被生长季始期推迟幅度为11.1 d·km^-1,生长季末期提前,导致生长季长度缩短幅度为22.6 d·km^-1。2)生长季长度和生长季始期空间格局相似,由西北高海拔地区向东南低海拔地区呈山地垂直地带性规律;生长季中期以36°N为界,呈纬度地带性规律,生长季末期以106°30′E为界,经度地带性变化规律显著。3)气候因子在植被不同生长阶段的主导作用不同,气温对六盘山物候变化影响最显著;3月气温升高促使夏季物候提前,9月降水增加促使秋季物候推迟;6月气温升高与9月降水增加导致耕地生长季中期显著推迟,灌木、林地生长季中期显著提前;生长季始期对3月日间最高气温的负敏感性最强,生长季末期对9月夜间最低气温的正敏感性最强,该结论与植被生长生理特征一致。更多还原

【Abstract】 As a vegetation vulnerability zone and sensitive area of climate change, mountain system directly reflects the response and adaptation process of mountain ecosystem to global environmental change.Based on GIMMS NDVI 3 g time series dataset in 1982-2015,this paper extracted the vegetation phenological parameters in Liupan Mountains using the dynamic threshold method of TIMESAT 3.3,and then combining with precipitation, temperature and sunshine datasets, this paper studied the variation of vegetation phenology and its response to climate change in Liupan Mountains using the methods of least-square and partial correlation analysis.It is found as follows.1) the SOS of vegetation was delayed by 11.1 d·km^-1,the LEN was shortened by 22.6 d·km^-1,which was mainly resulted by the advance of EOS.2) The spatial distribution pattern of SOS was similar with the LEN,which showed a vertical direction zonality of mountain from the high altitude area in the northwest to the low altitude area in the southeast.MOS was bounded by 36°N and showed the latitudinal direction zonality, while EOS was bounded by 106°30′E and presented significant longitude direction zonality.3) Different climate factors played different roles in different growing periods of vegetation.Temperature had the most significant effect on the phenological changes in Liupan Mountains, the increase of temperature in March led to the advance of summer phenology, and the increase of precipitation in September led to the delay of autumn phenology.The increase of temperature in June and precipitation in September significantly delayed the MOS of cultivated land, and advanced the MOS of shrub and forest.The negative sensitivity of SOS to the highest daytime temperature in March was the strongest, and the positive sensitivity of EOS to the lowest night temperature in September was the strongest, this conclusion is consistent with the physiological growth characteristics of vegetation.更多还原