The characteristics of herbaceous plant communities in the southeast of Motianling northern slope at different altitudes

Altitude is the dominant factor that influenced vegetation habitat differences which has a profound influence on ecosystem structure and process. The present study analyzed plants diversity and primary productivity of community in altitude of 600-1 500 m range in the southern section of Motianling northern slope using the analysis of correlation, stepwise regression and the test of Pearson correlation coefficient. The results showed that the species abundance was significantly and positively correlated (R2=0.278 4) with the altitude gradient (P0.05), whereas plant coverage was significantly and negatively correlated (R2=0.43) with the altitude gradient and there was weak correlation between altitude gradient and vegetation height and density (P0.05). Furthermore, aboveground biomass firstly increased and then decreased with the increase of altitude, however, underground biomass changed more complicated which firstly increased, then decreased, and increased again with the increase of altitude. The variations of plant functional group of aboveground biomass and underground biomass were consistent with the variations of altitude gradient. All of the results showed that the characteristics of herbaceous communities had a significant change with attitude gradient in the southeast of Motianling northern slope. The difference of aboveground and underground biomass for each functional group was significant. There was highly significant positive correlation between biomass and the vegetation coverage of the herb layer (P0.01), and no correlation between biomass and plant height and density; between plant coverage, height and density.