Responses of Natural Vegetation Dynamics to Climate Drivers in China from 1982 to 2011
Responses of Natural Vegetation Dynamics to Climate Drivers in China from 1982 to 2011
复制标题
1982-2011年中国自然植被动态对气候驱动因素的响应
DOI：
10.3390/rs70810243
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发表时间：
2015-08-01
期刊：
影响因子：
5
通讯作者：
Lei, Huimin
中科院分区：
文献类型：
--
作者：
Liu, Yanlan;Lei, Huimin
利用归一化植被指数（NDVI）和气候驱动因子数据，研究了1982 - 2011年中国植被生长的时空变化及其气候驱动因子的影响。分析了NDVI年际时间序列的长期变化趋势、意义和突变点。我们应用简单回归和多元回归模型来量化气候驱动因素对植被生长的影响，并比较它们的相对贡献。结果表明，1982 - 2011年，生长季NDVI平均增加0.0007a-1，有76.5%的研究区域呈现增加趋势。从季节上看，春季和秋季的NDVI增长率较高，而夏季变化较小。在全国范围内，生长季NDVI与温度和降水量呈显著正相关，温度是主导因子。在区域尺度上，生长季NDVI在中国南方大部分森林覆盖区主要受气温升高的影响，而在中国北方大部分草原区主要受降水的影响。在过去的30年中，全国平均NDVI的增长趋势在1994年突然改变，从0.0008年-1减缓到0.0003年-1。从区域特征来看，自20世纪90年代中期以来，中国南方森林覆盖区生长季NDVI随气温升高而加速，而自2000年前后以来，中国北方部分草地的生长季NDVI随气温升高而减缓，降水量减少。典型区域分析表明，除气候驱动因子的长期变化趋势和突变点外，植被指数的变化过程还受到干旱和造林等外部因子的影响。植被生长对气候驱动因子的非线性响应以及非气候因子对植被生长的影响有待进一步研究。
This study investigated the spatiotemporal variation of vegetation growth and the influence of climatic drivers from 1982 to 2011 across China using datasets from the Normalized Difference Vegetation Index (NDVI) and climatic drivers. Long term trends, significance and abrupt change points of interannual NDVI time series were analyzed. We applied both simple regression and multi-regression models to quantify the effects of climatic drivers on vegetation growth and compare their relative contributions. Results show that on average, the growing season NDVI significantly increased by 0.0007 year-1, with 76.5% of the research area showed increasing NDVI from 1982 to 2011. Seasonally, NDVI increased at high rates during the spring and autumn while changed slightly during the summer. At a national scale, the growing season NDVI was significantly and positively correlated to temperature and precipitation, with temperature being the dominant factor. At regional scales, the growing season NDVI was dominated by increasing temperature in most forest-covered areas in southern China and dominated by precipitation in most grassland in northern China. Within the past three decades, the increasing trend of national mean NDVI abruptly changed in 1994, slowing down from 0.0008 year-1 to 0.0003 year-1. To be regional specific, the growing season NDVI in forest covered southern China has accelerated together with temperature since mid 1990s, while parts of the grassland in northern China have undergone stalled NDVI trends corresponding to slowed temperature increment and dropped precipitation since around 2000. Typical region analysis suggested that apart from long term trends and abrupt change points of climatic drivers, the processes of NDVI variation were also affected by other external factors such as drought and afforestation. Further studies are needed to investigate the nonlinear responses of vegetation growth to climatic drivers and effects of non-climate factors on vegetation growth.