Global Change Biol:北京师范大学赵祥课题组揭示全球植被对气候变化
2015年9月，北京师范大学地遥学院赵祥副教授与硕士生武东海以及其他合作者，在Global Change BioLogy上发文阐述了植被对气候变化的滞后响应，并评价了其在全球变化研究中的重要性。文章题为"Time-lag effects of global vegetation responses to climate change"。
全球气候变化显著影响陆地生态系统中植被的生长。受气候变化时空差异性与生态系统空间异质性的影响，植被对气候变化的响应存在非常大的差异，表现为空间响应的多样性与时间响应的滞后性。南北半球中高纬度地区(30N-90N，30S-90S)植被对于当月温度的相关性最强，低纬度地区(30S-30N)植被多数区域的滞后时间超过1个月。北半球高纬度大部分植被对降水未表现出滞后响应，干旱半干旱地区对降水响应的滞后时间大约为1个月。北半球高纬度植被对辐射有1个月的滞后期，全球其他地区对辐射滞后时间的差异性较大，但大部分滞后时间都超过1个月。
与此同时，全球植被生长的气候驱动因子在空间上也表现出显著的差异。在北半球高纬度地区主要受到温度的影响，在干旱半干旱地区主要受到降水的影响，在美国东部等地区主要受到辐射的影响。
揭示植被对气候变化响应特征的时空格局是深入理解气候变化对植被影响的前提，也是定量评价未来气候变化影响的基础。之前对于大尺度植被气候交互效应的研究大多使用相同时刻的气象因子和植被指数建立模型，较少考虑植被对气候因子响应的时滞效应，在一定程度上忽略了植被对气候响应的内在机制，进而增大了模型模拟结果的不确定性。
原文链接：
Time-lag effects of global vegetation responses to climate change
原文摘要：
Climate conditions significantly affect vegetation growth in terrestrial ecosystems. Due to the spatial heterogeneity of ecosystems, the vegetation responses to climate vary considerably with the diverse spatial patterns and the time-lag effects, which are the most important mechanism of climate-vegetation interactive effects. Extensive studies focused on large-scale vegetation-climate interactions use the simultaneous meteorological and vegetation indicators to develop models; however, the time-lag effects are less considered, which tend to increase uncertainty. In this study, we aim to quantitatively determine the time-lag effects of global vegetation responses to different climatic factors using the GIMMS3g NDVI time series and the CRU temperature, precipitation, and solar radiation datasets. First, this study analyzed the time-lag effects of global vegetation responses to different climatic factors. Then, a multiple linear regression model and partial correlation model were established to statistically analyze the roles of different climatic factors on vegetation responses, from which the primary climate driving factors for different vegetation types were determined. The results showed that (1) both the time-lag effects of the vegetation responses and the major climate driving factors that significantly affect vegetation growth varied significantly at the global scale, which was related to the diverse vegetation and climate characteristics; (2) regarding the time-lag effects, the climatic factors explained 64% variation of the global vegetation growth, which was 11% relatively higher than the model ignoring the time-lag effects; (3) for the area with a significant change trend (for the period 1982 - 2008) in the global GIMMS3g NDVI (p < 0.05), the primary driving factor was temperature; and (4) at the regional scale, the variation in vegetation growth was also related to human activities and natural disturbances. Considering the time-lag effects is quite important for better predicting and evaluating the vegetation dynamics under the background of global climate change.
作者：赵祥
