Abstract: With“soil-crop-animal”food chain as a clue, the samples of different type of soils, main crops and animal-poultry products were collected in red soil agro-area in Northern Hunan and their contents of main trace elements(Cu,Fe,Zn,Mn,Co and Se) were determined in present study. The results showed that the content order from high to low of each element in four kinds of soil was Fe > Mn > Zn > Cu > Co > Se. The contents of Cu and Zn were significantly related (p>0.01), while the contents of the other elements were not related. The contents of the same element in different crops were different. For example, the content order of Cu in different crops was soybean > peanut > green bean > rape seed > rice > maize. A common characteristics is that the contents of any trace element were higher in crops which grew on the soil with higher contents of the elements. The contents of each element in the same animal product were also different. For example, the contents of Zn and Fe were higher and the contents of Mn and Cu were lower in pork. The content order of Fe and Cu in different animal products was liver of pig> liver of chicken>pork >chicken meat >beef>goat meat>egg.

Key words: landscape pattern, land cover, soil erosion, landscape leakiness index.