Abstract: By using the survey methodology of community ecology, a total of 85 sampling plots were installed in the lower reaches of Fenhe River Basin in Shanxi. According to the occurrence frequency of the investigated herbaceous species, 21 dominant species were selected for interspecies association analysis. The associations between dominant species were determined based on the χ² inspection and in light of the association coefficient (AC) and the percentage co-occurrence (PC). The functional groups of herbaceous plants in the study area were classified by the associations between dominant species and the variations of moisture gradient. Overall, the 210 species pairs formed by the dominant species showed negative association, but the vast majority of the species pairs showed weak association and non-association. Four herbaceous plant functional groups were classified, i.e., aquatic, hygrophyte, mesoxerophyte, and invasive. Significant positive association was shown between the species in the same functional groups, and negative association or nonassociation was shown between the species of different functional groups.

Key words: apple, nitrogen, Malus hupehensis, absorption, potassium level, utilization.