| In order to understand the effect of the change of limited element on degraded grass restoration at arid sunny-slope in Great Xing’an Mountains on plant dynamic, we took arid sunny-slope of Great Xing’an Mountains as the research object, after studying the impact of adding N and P fertilization for two years in a row above on the variation law of aboveground biomass, plant diversity and soil and plant chemical metrological characteristics, the conclusions followed as:1、N was the main factor to limite the restoration of system in ecosystem of arid sunny-slope in Great Xing’an Mountains, and N:P in plant increased gradually with N addition increasing. The limited element was changed from N limitation to P limitation.N addition, which leaded to the change of community composition with different treatments, but cyperaceae was dominant species of the community in a short term, which suggested fertilization didn’t lead to rapid rate of community succession.2、Species diversity of the plant community had no obvious change after N and P addition. Therefore, it was difficult to recover the plant diversity on degraded grass restoration at arid sunny-slope in Great Xing’an Mountains.3、The concentrations of total nutrient and available P in soil had no obvious change after N addition, and the concentrations of NH4+-N and NO3--N in soil increased greatly with the mass of N addition. Total and available nutrient had no obvious change after the additionof P fertilization either. The concentration of total N in plant increased with the increase of N addition, and the concentration of total P in plant increased with the increase of P fertilization addition. There were significant effects on plant to absorb N, P after N and P addition.4、Concentrations of total nutrient and stoichiometric ratio of plant had no correlation with the species diversity of plant communities as a whole. N:P in plant had significant correlationwith total N, NH4+-N, NO3--N and available P in soil. |
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