The Effect Of Nitrogen Deposition On Soil Microbial Diversity In Larix Gmelini Forest

This experiment from 2011 to the greater hinggan mountains south WengHe nature reserve of simulated nitrogen deposition experiment sing-an larch forest.This experiment adopts four groups of processing,low nitrogen(T_L,2.5gN·m^-2·yr^-1),medium nitrogen(T_M,5gN·m^-2·yr-¹),high nitrogen(T_H,7.5gN·m^-2·yr^-1),and contrast?CK,no N?,repeat 3 times.This experiment in May,2015-September in experimental sample was taken to the ground in the soil samples were analyzed,and tries to reveal the effects of nitrogen deposition on sing-an larch forest.The experimental results are as follows:?1?The performance of nitrogen deposition on soil pH is,increase with the increase of soil depth.?2?Nitrogen deposition on soil total carbon,the performance of total nitrogen and total phosphorus is the different nitrogen in different seasons all carbon appeared to increase after the decrease trend,but the difference is not significant,with the deepening of the soil;Soil total phosphorus along with the deepening of the soil reduce,,there is no significant difference between different soil layer;With total nitrogen increased with increasing nitrogen deposition,shallow soil?0¹0cm?than the deep soil?10²0cm?are more likely to be affected.?3?Nitrogen deposition on the performance of nitrate nitrogen and ammonium nitrogen in different seasons,the content of nitrate nitrogen and ammonium nitrogen increased with the increase of nitrogen deposition increases,topsoil significantly increase the trend of the deep soil,and the trend of nitrate nitrogen increases than ammonium nitrogen.?4?A significant impact on soil nitrogen deposition summer,summer with microbial biomass carbon nitrogen deposition first increase then decrease then increase trends;The increase of soil carbon and nitrogen on the microorganism inhibition effect.But in 10to 20cm of soil,the correlation is not obvious.?5?Nitrogen deposition in different seasons are influential to fungi,but not dramatically.Fungi in the soil of the richness index and diversity index was no significant change.In tested soil fungi have response to soil of nitrate nitrogen,the higher performance for soil of nitrate nitrogen,the higher the abundance of the fungus,but the change of nitrate nitrogen and fungal diversity has no obvious correlation.?6?Soil fungi tested components have response to nitrogen deposition,at the gate level ascomycetes and basidiomycetes have response to nitrogen deposition,russula fungi in the level of nitrogen deposition has a response.?7?Bacteria respond to nitrogen deposition is not obvious,richness index and diversity index shows the trend to reduce,increase,decrease,but the difference is not significant;Deformation bacteria on the level of the door,door,the door acid bacillus,the green curved actinomycetes door and door are on the increase of nitrogen deposition has a response;In the level,the slow rise rhizobia have response to nitrogen deposition.