Comparative Study Of Characteristics Between Legume Community And Aneurolepidium Chinense Community On Songnen Grassland

Songnen grassland is very important to the development of stock raising in the northeast of China, Long-term extensive operation modality, both declined soil fertility and reduced vegetation productivity. Leguminous plant has been thinking highly because its high protein content, good palatability, higher productivity, economic and high-performance nitrogen fixation is attracted increasing attention. Biomass is one of the criteria on measuring productivity of grassland, which represents the capacity of ecosystem on utilizing materials and energy.This research based on leguminous plant, which is a common plant on Songnen grassland, depicts the seasonal dynamics of Aneurolepidium chinense + Lathyrus quinquenervius community and L. chinensis community's aboveground biomass, analyses the changes of growth rate, the characteristics of vertical distribution on biomass and the regularity of regeneration; to reveal the quantitative trait of leguminous plant communities, and also compare with the differences on community characteristics and soil properties between leguminous plant communities and L. chinensis community, the results show that:On Songnen grassland, the aboveground biomass curve by seasonal dynamics showed a single peak on L. chinensis + L. quinquenervius community and L. chinensis community. In August it reached the maximum point, excellently coincident with Logistic growth curve. The AGR of the two communities's aboveground biomass in the growing season showed bimodal changes, but demonstrated that RGR performance monotone decreasing trend. L. chinensis + L. quinquenervius community have higher value of AGR and RGR than L. chinensis communities. L. chinensis + L. quinquenervius community and L. chinensis community had the maximum regeneration after the first time sampling, and then decreased gradually. L. chinensis + L. quinquenervius community had lower pH and conductivity in soil than L. chinensis community, the soil under L. chinensis + L. quinquenervius community had significantly higher total nitrogen concentration than L. chinensis community in 0 ~ 15 cm soil layer.L. chinensis + L. quinquenervius community and L. chinensis community had the same trend on aboveground biomass vertical distribution, which is increased at first and then decreased. There was a small proportion under 7.5 cm layers on aboveground biomass, but L. chinensis community below 7.5 cm layer had larger proportion of biomass than L. chinensis + L. quinquenervius community. Light transmission rate of community canopy increased as height increased, which has significant correlation with the vertical distribution of aboveground biomass.Leguminous plant communities had higher species richness than the control of L. chinensis. More than 60% is made up of Gramineae, Compositae and Leguminosae species. The relationship between productivity and diversity of leguminous plant community monotone decreased. There was greater cover of Leguminous plant communities than that of control; there was not significant difference between Medicago falcate communities and control on the cover.The average height of L. chinensis in leguminous plant communities was higher than the control of L. chinensis community. With regards to height frequency distribution of L. chinensis community, they are normal distribution except for the control community in Vicia amoena community, and furthermore, there is little positive skewness. There were not significantly differences between leguminous plant communities and L. chinensis community on the single plant weight, however, the biomass of leguminous plant communities is higher than the control of L. chinensis community. The pH and conductivity of the soil layers in leguminous plant communities were lower than in L. chinensis community.