Abstract: To understand the change process and change pattern of cropland in Taizhou region of Jiangsu Province, the dynamic change of cropland percentage coverage (CPC) in the region from 1995 to 2006 was analyzed, based on the Landsat TM images of 1995, 2000, and 2006  by the method of neighborhood analysis. In 1995-2006, the cropland area in the region reduced continuously. The average relative amplitude of the variation of CPC decreased with increasing CPC from 0 to 80%, reached a minimum at 80%, and then increased with increasing CPC from 80% to 100%. The curves of pixel frequency-CPC in 1995, 2000, and 2006 showed similar mono-peaked patterns, but the peak values and their corresponding CPC decreased from 1995 to 2006. The 40%-80% CPC zones accounted for about 90% of the area change of the cropland in the study period. The area proportion of the 60%-80% CPC zones decreased significantly, while that of the 40%-60% CPC zones increased rapidly. The reduction rate of CPC was prone to be increased in the areas with relatively dense settlements and roads. The results showed that the stability and the area change rate of the cropland in the region were both closely related to local CPC.

Key words: Polycyclic aromatic hydrocarbons (PAHs), Glucose, Sphingonumas sp.