Abstract:
In order to determine the reliability of soil color indexes for identifying the terrain and climate factors,the Munsell color chart was used for examining soil color of grassland in Yunnan Province.The results showed that the soil color distribution was obviously restricted by elevation and region.After the analysis of relationship between altitude,mean annual temperature,mean annual precipitation and soil color,including chroma,value,hue and redness rating,we provided that soil value had a significant correlation with altitude,temperature and precipitation (p<0.01),that was,soil value increased with decreased altitude and hot-humid weather.However,in this study,the correlation between soil redness rating and climatic factors was not significant.Which indicated that soil value would be more suitable for reflecting regional climate change,just as Yunnan Province that has complex topography and geomorphology,and soil redness rating would represent the large scale and long ages climate change.So soil color may not always be consistent with the climatic factors,and other factors,such as landform,physiognomy and temporal scale,which could be taken into account when we calculate climate indices through soil color,and the most representable color index should be chosen according to the research area.