长白山区植被生长季NDVI时空变化及其对气候因子敏感性

本文利用长白山区SPOT/VGT NDVI 数据和气象数据，分析该区不同植被类型NDVI时空变化特征以及与气候因子的相关关系，并探讨了植被对气候变化响应的滞后性。结果表明：①2000-2009 年，长白山区植被NDVI 逐年变化总体呈增长趋势，增长区域的面积占全区面积的83.91%，在空间上主要集中在北坡和西坡，NDVI减少区域集中在南坡；②NDVI变化率随季节和植被类型变化而不同，NDVI增长主要集中在5 月和9 月，而7 月NDVI变化较小，甚至出现下降趋势；③植被NDVI与温度和降水存在着显著的正相关性（p<0.01），且NDVI与温度的相关性高于与降水的相关性，且随海拔升高，NDVI与温度相关性增强；④NDVI对气温和降水变化的响应存在滞后期， 不同植被类型，滞后期存在差异。苔原NDVI对温度和降水响应的滞后期大约10 天，而针阔混交林和针叶林NDVI 对温度和降水响应的滞后期约为20 天。

Spatial-temporal Variation of NDVI in the Growing Season and Its Sensitivity to Climatic Factors in Changbai Mountains

In order to reveal the response of mountain ecosystem to climate change,the spatial-temporal distribution of vegetation variation in the Changbai Mountains was investigated by using the 10-day SPOT/VGT NDVI data from 2000 to 2009.Combining the meteorological data,we discussed the relationship between NDVI and climatic factors and time lags of vegetation variation response to climate change.The results are shown as follows.1) NDVI increased from 2000 to 2009 in Changbai Mountains.The NDVI increased and decreased area covered about 83.91% and 16.09% of the whole study area respectively.The increased area was mainly distributed on the northern and western slopes,while the decreased area was distributed on the southern slope.The growth rate of NDVI centralized 0-0.006 /a.2) The change rate of NDVI varied by seasons and vegetation types.The peak of NDVI slope appeared in May and September,but no increase,even a little decrease was observed in July;3) There was a significantly positive correlation between NDVI and climatic factors(temperature and precipitation),and NDVI had a closer correlation with temperature than with precipitation for the three vegetation types.The results also revealed that a correlation between NDVI and temperature in tundra zone was stronger than that in the Korean pine-broadleaved mixed forest(700-1100 m) and coniferous forest(1100-1700 m),which indicated that vegetation at higher elevation is more sensitive to temperature change;4) The correspondence between NDVI and climatic factors had a marked time lag for 10-20 days for the whole study area.Different vegetation types had different time lags.The response of NDVI in tundra zone to climatic factors had a time lag of about 10 days,while in the two forests mentioned above,the response had a time lag of about 20 days.