Interspecific association of dominant herbaceous species in cold temperate coniferous forest of Ma Kehe Forest Region in San Jiangyuan,northwestern China

Ma Kehe Forest Region is one of the core areas in San Jiangyuan National Nature Reserve. A large number of herbaceous species distribute in the cold temperate coniferous forest region,and they play important role in the process of earlier succession and ecological restoration of the cold temperate coniferous forests. A series of techniques,including related tests,calculation of the percentage of co-occurrence and association coefficient,had been used to analyze the interspecific association among 22 dominant herbaceous species in 40 plots in Ma Kehe Forest Region. The results showed that over half of dominant herbaceous species could appear in the same community and presented positive interspecific association,but the degree of positive association was very weak,118 pairs of species showed their positive correlation and 112 pairs of species showed their negative correlation in 231 pairs of herbaceous species,only one pair of species was of absolute independent correlation. So over half of dominant herbaceous species were positive interspecific association,and most of them had opportunity to use the same resources and occupy similar niche in the same community,but there was almost no significance interspecific associations; near half of dominant herbaceous species were negative interspecific association due to their competitions in Ma Kehe Forest Region.