青藏高原高寒草地物候沿海拔梯度变化的差异分析

发布时间：2018-04-30 11:53

本文选题：物候 + 高寒草地　；参考：《地理研究》2017年01期

【摘要】：探讨高寒草地物候变化的海拔敏感性有助于揭示气候—植被的关系。基于2000-2013年的SPOT-VGT(NDVI)和MODIS(NDVI和EVI)、DEM、生态地理区划以及草地矢量数据,分析青藏高原高寒草地物候变化与海拔的关系。结果表明:1青藏高原高寒草地返青期和枯黄期分布随海拔上升呈现相对一致的规律性;但其年际变化趋势随海拔上升呈现明显差异。2返青期的提前趋势大致以3200 m为界线,其下提前幅度随海拔上升显著增大,其上则相反。但枯黄期年际变化趋势随海拔上升则先呈现推迟趋势,且推迟幅度逐渐减小;之后呈现提前趋势,且提前幅度持续增大。3将高原中部的青南高寒草甸草原区(IC1)和南部的藏南山地灌丛草原区(IIC1)高寒草地物候变化趋势进行对比,两分区呈现相反的年际变化趋势;随海拔上升,两分区返青期的年际变化趋势呈现相反的变化方向,枯黄期则呈现基本一致的变化方向。上述差异表明,基于遥感反演的高寒草地物候年际变化趋势的垂直分异特征难以直接反映高原增温的海拔效应。
[Abstract]:To explore the altitude sensitivity of phenological changes in alpine grassland is helpful to reveal the relationship between climate and vegetation. Based on SPOT-VGTN NDVI (2000-2013), MODIS(NDVI and EVI Dem, the relationship between phenological changes and altitude of alpine grassland in Qinghai-Xizang Plateau was analyzed. The results show that the distribution of the alpine grassland in the Qinghai-Tibet Plateau is relatively consistent with the elevation, but the trend of interannual variation is obviously different with the elevation. 2 the early trend of the green stage is roughly 3200 m, and the distribution of the alpine grassland in the Qinghai-Xizang Plateau is relatively consistent with the rise of altitude. The lower advance range increases significantly with the elevation, but the upper one is opposite. However, the trend of interannual variation in the low yellow period was delayed at first and decreased gradually with the elevation rising, and then showed an advance trend. By comparing the phenological changes of the alpine meadow grassland in the central part of the Qinghai Plateau with that of the southern Tibetan shrubbery grassland (IIC1), the phenological changes of the alpine grassland in the two subzones showed a contrary interannual trend with the elevation increasing, and the range of advance was increased continuously, and the results showed that the phenological changes of the alpine meadow in the central part of the plateau were different from those in the southern part of Tibet. The trend of interannual variation of the two regions in the green stage showed the opposite direction, and the trend of the change was basically the same in the low yellow period. These differences indicate that the vertical differentiation characteristics of the phenological variation trend of alpine grassland based on remote sensing inversion can not directly reflect the altitude effect of plateau warming.
【作者单位】：陆地表层系统分析与模拟院重点实验室中国科学院地理科学与资源研究所;江西师范大学鄱阳湖湿地与流域研究教育部重点实验室;中国科学院大学;
【基金】：中国科学院战略性先导科技专项(XDB03030500) 国家自然科学基金项目(41201095,41371120)
【分类号】：S812.1

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