SCIENTIA GEOGRAPHICA SINICA ›› 2013, Vol. 33 ›› Issue (5): 594-601.doi: 10.13249/j.cnki.sgs.2013.05.594

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Research on Vegetation Changes and Influence Factors Based on Eco-geographical Regions of Inner Mongolia

Qing-yu ZHANG1,2, Dong-sheng ZHAO1, Shao-hong WU1, Er-fu DAI1   

  1. 1.Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101,China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2012-07-05 Revised:2012-10-11 Online:2013-05-20 Published:2013-05-20

Abstract:

This study constructed growing season NDVI in 1982-2011 based on GIMMS and MODIS data in Inner Mongolia. The spatial and temporal characteristics of inter-annual NDVI changes were analyzed and natural and human influence factors were investigated in different eco-geographical regions. The results show that, linear regression equation is a good method to modify NDVI in GIMMS and MODIS remote images. The growing season NDVI increased on the whole and the increase rate was 0.265% and displayed significant inter-annual fluctuations in the past 30 years. NDVI decreased significantly in 1982-1986, then increase significantly during 1997-2002, and relative steady phases were in 1986-1997 and in 2002-2011. NDVI that increased most significantly were located in the northern of Inner Mongolia. However, there were 5.075% regions decreased which mainly distributed on typical steppe in Hulun Buir and Xilin Gol. NDVI change rates of different vegetations from eco-geographical region were in the following order: farm and shrub > forest > farm and typical steppe > meadow and meadow steppe > typical steppe and farm > typical steppe > desert steppe > desert. NDVI change rate was fastest in IIC2 eco-geographical region which was 0.277 and slowest in IID2 eco-geographical region which was 0.001. NDVI was significantly correlated with precipitation in most regions and presented obvious strap regularity from east to west, which was negative correlation in the eastern region, positive correlation in center region and no correlation in the western region. However, great differences existed in different eco-geographical region of Inner Mongolia. Eco-geographical region of IIA3, IA1 had biggest correlation which more than 0.5 but significant negative correlate between NDVI and precipitation in all regions. NDVI had little significantly positive correlations with temperature in Inner Mongolia whose correlations were less than 0.2 in most eco-geographical regions. However, NDVI exhibited significant positive correlations with temperature in highland desert steppe region of Western Inner Mongolia and highland steppe region of Eastern Inner Mongolia. Vegetation that influenced by human activities was gradually increased with the increase of vegetation complex degree in the last 30 years. There are most effects by human activities in IIC1, IIC2, IIIB3 eco-geographical region which located on the south of the Da Hinggan Mountains and least effects in IA1, IIB2, IIA3 eco-geographical region which distributed in the northeastern of the mountains. In the areas where human activities heavily restrained NDVI increased by 41.165%, and they were located in IIC3, IIC4 and IID2 eco-geographical region, in the other eco-geographical regions NDVI were promoted about 58.835% obviously. In IIC1, IIC2, IIIB3 eco-geographical region human activities promote NDVI most significantly. NDVI was promoted by national policies such as the natural forest protection project, conversion of cropland to forest and grassland project, desertification treatment and so on. However, over grazing, excessive reclamation, rapid urbanization etc could lead NDVI decrease.

Key words: eco-geographical regions, NDVI, Inner Mongolia, influence factors, correlation coefficient

CLC Number: 

  • K903