A measure for spatial heterogeneity of vegetation in the Center of Inner Mongolia

Song, Baimin; Huang, Daming; Wang, Renqing; Shiyomi, Masae; Xu, Fu-Liu; Wang, Wei; Zhang, Gaosheng; Zhang, Xianqiang; Qiao, Jie

doi:10.1016/j.pnsc.2007.07.015

Cited by 9 publications

(1 citation statement)

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“…The warming rate was higher than the average level of the warming across the rest of the country over the past 50 years and particularly since 1988, while at the same time, annual precipitation has varied substantially (Qin et al 2005;Ding et al 2006;Hou et al 2008;Yiu et al 2008). Some studies indicated the spatial heterogeneity of vegetation in the region (Song et al 2008), while other studies have focused on the relationship between vegetation and climate change, especially precipitation and temperature (Li and Shi 2000;Zhang et al 2001;Chen and Zheng 2008;Tao et al 2008). However, few studies have investigated the possible controls of geographic factors such as elevation, slope and aspect on vegetation pattern and greenness trend and variation (e.g., restoration or degradation of vegetation and the sensitivity of vegetation) which has been proved important (Pickup and Chewings 1996) especially in mid-eastern Inner Mongolia where geographic and climatic transitions are typical.…”

Section: Introductionmentioning

confidence: 99%

Trends and variation in vegetation greenness related to geographic controls in middle and eastern Inner Mongolia, China

2010

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Extensive studies have investigated the relationships between climate change and vegetation dynamics. However, the geographic controls on vegetation dynamics are rarely studied. In this study, the geographic controls on the trends and variation of vegetation greenness in middle and eastern Inner Mongolia, China (mid-eastern Inner Mongolia) were investigated. The SPOT VEGETA-TION 10-day period synthesis archive of normalized difference vegetation index (NDVI) from 1999 to 2007 was used for this study. First, the maximum value compositing (MVC) method was applied to derive monthly maximum NDVI (MNDVI), and then yearly mean NDVI (YMNDVI) was calculated by averaging the MNDVIs. The greenness rate of change (GRC) and the coefficient of variation (CV) were used to monitor the trends and variation in YMNDVI at each raster grid for different vegetation types, which were determined from a land use dataset at a scale of 1:100,000, interpreted from Landsat TM images in 2000. The possible effects of geographic factors including elevation, slope and aspect on GRC and CV for three main vegetation types (cropland, forest and steppe) were analyzed. The results indicate that the average NDVI values during the 9-year study period for steppe, forest and cropland were 0.26, 0.41 and 0.32, respectively; while the GRC was 0.008, 0.042 and 0.033 per decade, respectively; and CVs were 10.2, 4.8 and 7.1%, respectively. Cropland and steppe shared a similar trend in NDVI variation, with both decreasing initially and then increasing over the study period. The forest YMNDVI increased throughout the study period. The GRCs of the forest also increased, although GRCs for cropland and steppe decreased with increasing elevation. The GRCs of cropland and steppe increased with increasing slope, but the forest GRCs were not as closely related to slope. All three vegetation types exhibited the same effects in that the GRC was larger on north-facing (shady) slopes than south-facing slopes due to differences in water conditions. The CVs of the three vegetation types showed different features to the GRC. The CVs for all three vegetation types were not affected by aspect. The CVs for forest and cropland showed minor effects with changes in elevation and slope, but the CV for steppe decreased with increasing slope, and increased with increasing elevations to 1,200 m, before decreasing at higher elevations. Our findings suggest that the role of geographic factors in controlling GRC should also be considered alongside climate factors.

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Section: Introductionmentioning

confidence: 99%