Effects Of Different Grazing Intensity On Arbuscular Mycorrhizal Function In Leymus Chinensis Meadow Steppe

This research based on the Leymus chinensis meadow steppe in Western Wuzhumuqin banner. The study result mainly concentration on the Leymus chinensis population mycorrhizal infection rate and the dominated plant population vegetation characteristics, the above-ground biomass of Leymus Chinensis population, community and the nutrient absorption under different grazing intensity. The main results were summaryed as follows:1. with increasing of grazing intensity Leymus chinensis mycorrhizal infection rates significantly decreased.2. with the treatment of mycorrhizal process, the height, coverage and density of dominated species were higher than no mycorrhizal affected process.The mycorrhizal effect of importance value of Leymus chinensis and Stipa baicalensis was the highest in the moderate area,but the mycorrhizal effect of importance value of Cleistogenes squarrosa was the highest in the no grazing area.3. The maximum of mycorrhizal effection of Shannon-Wiener and Simpson diversity index was in the no grazing area, the mycorrhizal effect of Margarlef richness index was the highest in the moderate area, the mycorrhizal effect of Pielou evenness index was the highest in the heavy area.There was the positive correlation between the mycorrhizal effect of Shannon-Wiener diversity index and Simpson diversity index, and the mycorrhizal effection Shannon-Wiener diversity index significantly difference between light and heavy area.4. The mycorrhizal effection of above-ground biomass of Leymus chinensis was highest in the moderate area. The mycorrhizal effection of above-ground biomass of community was highest in the light area.5. The mycorrhizal effection of nitrogen concentration of Leymus chinensis population, nitrogen concentration and nitrogen resorption of community, phosphorus concentration and phosphorus resorption of community in light and no grazing area were higher than the moderate and heavy area. The mycorrhizal effection of nitrogen resorption, potassium concentration and potassium resorption of Leymus chinensis in the moderate and heavy area were higher than in light and no grazing area. The mycorrhizal effection of phosphorus concentration and phosphorus resorption of Leymus chinensis were highest in the light area. The mycorrhizal effection of potassium concentration and potassium resorption of community were highest in the no grazing area.