气候变化可以通过影响植被物候来影响生态系统过程,但气候变化过程对区域尺度物候影响尚未达成共识,特别是地形起伏较大、生态系统多样性丰富度较高的区域.基于MODIS EVI数据,运用Savitzky-Golay(S-G)滤波、动态阈值、Anusplin插值、Theil-Sen斜率、Mann-Kendall检验和偏相关分析等方法,分析了2001-2019 年的三江并流区植被物候的时空分布特征及植被物候与气候要素变化之间的关系.结果表明:(1)三江并流区植被物候的生长季始期(SOS)主要集中在第80-140 d,生长季末期(EOS)集中在第 290-330 d,生长季长度(LOS)介于180-240 d之间;整体上东北部高海拔区域生长季始期和末期早于西南河谷区域,河谷区域的生长季长度大于东北部高海拔区域.2001 年以来呈现出生长季长度增加、生长季始期提前、生长季末期延迟的趋势.(2)植物生长季始期主要受降水和气温影响,温度对生长季始期的影响也表现为正相关.(3)生长季末期受气温和降水的影响表现出明显的区域差异,东北部高海拔区域主要受到气温的正向影响,西南部河谷区域则主要受降水的负向影响.(4)生长季长度与 6-9 月份的气温和降水呈正相关关系,其中 6 月份和 9月份的气温为主导因子,7-8 月份降水的影响高于气温.
Global climate change affects ecosystem processes by altering vegetation phenophases,but there is few consensus on how vegetation phenophases respond to climate change on a regional scale.Especially the regions with large topography and high ecosystem diversity and richness.Then it can improve the analysis of regional differences in climate change impact mechanisms.Depends on the MODIS EVI data,Savitzky-Golay(S-G)filtering,dynamic threshold method,Anusplin interpolation,Theil-Sen slope,Mann-Kendall trend test and partial correlation analysis were used to detect the spatial and temporal distribution characteristics of vegetation phenology in the Three Parallel Rivers region from 2001 to 2019 and explore the correlation between vegetation phenology and climate elements changes.The results show that:①The start of the growing season(SOS)of vegetation in the Three Parallel Rivers Region is mainly concentrated from 80d to 140d,the end of the growing season(EOS)is concentrated from 290d to 330d,and the length of the growing season(LOS)is mainly from 180d to 240d.Overall,SOS and EOS in the northeastern high-elevation region is earlier than that in the southwestern high-elevation region,and LOS in the valley region is longer than that in the northeastern high-elevation region.Since 2001,there has been a trend of increasing LOS,advancing SOS,and delaying EOS.②SOS is mainly influenced by precipitation and temperature,with precipitation becoming the dominant factor affecting SOS in March and April,and the effect of temperature on SOS always shows a positive correlation.③The influence of temperature and precipitation at EOS showed significant regional differences,with the northeastern high-elevation region being mainly influenced positively by temperature and the southwestern river valley region being mainly influenced negatively by precipitation.④LOS was positively correlated with temperature and precipitation from June to September,with temperature being the dominant factor in June and September and precipitation having a higher effect than temperature from July to August.