Analysis to the interspecific association of Stellera chamaejasme population and other main plant species in Cleistogenes squarrosa steppe

Using variance test and 2×2 contingency table method, quantitative analysis to the overall interspecific association among the main plant species, and between Stellera chamaejasme and any other main plant species for the three grazing successional stages (heavy, over and extreme) on Cleistogenes squarrosa steppe was made in the paper. The results indicated that:(1)with the processing of the retrogressive succession, the overall interspecific association among main plant species of the communities transformed from significant positive to null; (2)interspecific association between Stellera chamaejasme and most of other plant species in the communities was insignificant, and interspecific relationships tended to be inter-independent; (3) of the heavey and over grazing stages, insignificant positive association but high association degrees were detected between Stellera chamaejasme and any other of the following: Cleistogenes squarrosa, Lespedeza daurica, Artemisia frigida, Enneapogon brachystachyum;(4) Stellera chamaejasme and Enneapogon brachystachyum displayed somewhat positive association in the three successional stages.