Effects Of AM Fungi On Soil Carbon And Nitrogen Under Warming And Nitrogen Deposition In Songnen Meadow Steppe

Arbuscular mycorrhiza fungi?AM fungi?is one of the most important soil microbes in the terrestrial ecosystems,which can form mycorrhizal association with more 80% terrestrial plant.AM fungi can improve plant growth by increasing nutrients and water uptake.The host plant supply the necessary carbohydrate to keep the growth of AM fungi.AM fungi can significantly enhance soil carbon?C?sequestration,increase the net primary productivity of ecosystems.Moreover,AM fungi can increase nitrogen?N?absorption and utilization,and alter N distribution among different plant species.However,the influence of AM fungi on soil C and N cyclings under global change is still not well understood.In the present study,we studied the effects of AM fungi on soil C and N under warming and N deposition in Songnen meadow.The research results are as follows:?1?AM fungi significantly increased the total soil C content across the four treatments.In the warming plus N addition treatment,AM fungi increased the total soil C content.?2?AM fungi significantly increased the soil N content?P< 0.05?under N addition.AM fungi also significantly altered the content of nitrate N and ammonium N.In warming,N addition,warming plus N addition treatments,AM fungi significantly reduced the content of soil nitrate N and ammonium N.?3?With the increase of temperature precipitation during growing season,soil respiration reached the maximum value.However,the single environmental factors and the role of AM fungi was not significant effect on soil respiration.There were significant interactive effects of N addition × AM fungi,warming × N addition × AM fungi on the soil respiration.?4?AM fungi significantly reduced the emission of soil N₂ O.AM fungi highly reduced the emission of N₂ O under the warming and N addition.AM fungi significantly reduced the CH₄ emission under N addition.In contrast,AM fungi significantly increased the release of CH₄ t under warming plus N addition.In summary,AM fungi had no significant impact on the soil C and N content and soil respiration in the short-term experiments under warming and N addition.AM fungi significantly altered the content of soil organic N and the emission of greenhouse under global change.AM fungi can alleviate emissions of greenhouse gases and reduce the negative effects of warming on grassland ecosystem.