|
|
Spatiotemporal characteristics of vegetation variation in Xilin Gol League in recent 15 years and its response to climate |
Jia Ruonan 1,2, Du Xin2, Li Qiangzi 2, Wang Hongyan 2 |
1. College of Geography & Tourism, Chongqing Normal University, 400047, Chongqing, China; 2. Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, 100101, Beijing, China |
|
|
Abstract [Background] Under the background of global change, vegetation dynamics and research on its relationship with climate is one of the focuses of the current international scientific problems. The study on the trend of vegetation coverage and response to climate is of great significance for global research, furthermore, it also benefits to global ecological processes and global ecological environment. [Methods] The annual and seasonal change trends of vegetation coverage were examined by employing MODIS-NDVI datasets in Xilin Gol League from 2001 to 2010, and then using Sen + Mann-Kendall model to analyze the significant level of the vegetation change further. In the end, based on the region of the meteorological data, mainly including the local temperature and precipitation, and using correlation analysis, the patterns of spatiotemporal variation of vegetation and its response to climate in Xilin Gol League during the period 2001—2015 was investigated. [Results] 1) The average vegetation NDVI showed a trend of greater volatility during 2001 to 2015 in the studied area, the change trend of process presented two waves, and the two higher values appeared in 2003 and 2012, of which 2008 vegetation NDVI appeared a temporary rise. Meanwhile, this highly correlated with the precipitation peak, it suggested that the increase of precipitation was a main reason of Xilin Gol League area vegetation to be improved. 2) The NDVI generally presented the distribution characteristics of “high in west and low in east冶, and this kind of distribution characteristics were consistent with the distribution of grassland type, from west to east in the order of desert grassland > typical steppe > meadow steppe. In terms of temporal characteristics, the overall trend was in rise, in detail, the trend was first rising after falling. The spatial distribution showed that NDVI increased significantly in southern and declined significantly in western. Significant increase in size for the grassland types was in the order of meadow steppe > typical steppe > desert grassland. 3) The peaks of NDVI were corresponding to the peaks of precipitation, but because of space differences in geographical location and climate conditions, the correlation between vegetation change and climate were different in each season and vegetation type, the vegetation variations were mostly influenced by precipitation in spring and summer, while it was controlled by temperature in autumn. [ Conclusions] The improvement of vegetation conditions in the studied area was closely associated with precipitation, although ecological measures like returning farming to forest benefited to the growing of vegetation, plenty of rainfall may guarantee the increase of vegetation coverage. Thus, only comprehending regional climate condition may play maximum function in ecological engineering.
|
Received: 26 May 2016
|
|
|
|
|
|
|
|