Abstract: The community characteristics and leaf C, N and P stoichiometry of Caragana davazamcii Sancz in the semi-mobile dune area, semi-fixed dune area and inter-dune lowland in the Mu Us sandy land were studied. The soil substrates of different habitats as well as the relationship between plants characteristics and soil conditions were studied. We found three major results: (1)The soil substrates of different habitats showed significant differences, i.e. the semi-mobile dune area had relatively poor and loose soil while the semi-fixed dune area and inter-dune lowland had relatively compact soil. (2)Length of current branches, weight of dry current branches, weight of dry leaves and leaf dry matter content were negatively correlated with the soil compaction, while leaf N:P ratio and leaf C:P ratio were positively correlated with the soil compaction. There was no significant relationship between leaf C:N ratio and soil compaction. (3)The crown, density and coverage of C.davazamcii Sancz from different habitats showed significant differences, which might be caused by the differences of soil compaction. In one word, soil compaction influenced the growth status of C.davazamcii Sancz, not only by affecting the above ground biomass and length of current branches, but also affecting the leaf C, N and P stoichiometry and the efficiency of nutrient contents of leaf.

Key words: Caragana davazamcii Sancz, stoichiometry, substrate, soil compaction