Dynamics Of Microbe Activities In Different Vegetation In Sloping Field On Loess Plateau

The article studies the seasonality dynamics changes of microbial activities in different vegetation in sloping field on Loess Platueau, in order to provide some theory of biology for recovering vegetation on Loess Platueau. So the seasonality changes of quantity of soil microbial and soil enzyme activity in different vegetation and microbial population and enzyme change in different slope were tested.The main results is:1. Changes of the microbial quantityTest the changes regulation of the quantity of bacteria,fungi and actinomycetes in different slopes and soil layers in Desolate land,Farmland,Medicago sativa L.,Caragana korshinskii ,Elaeagnus angustifotia,Prunus armeniaca,Platrhadus orientalis and Robinia Pseudoacacia.1.1 Regularity of the soil microbial quantity change seasonallyThe quantity of soil microbial change is more stability in spring and autumn,has no big motion and the change regularity is consistent in bacteria change.The amount of soil microbial is lower in Caragana korshinskii, Farmland and Medicago sativa L. Except the Caragana korshinskii and Desolate land,the amount of soil microbial is more in other vegetation in summer. To fungi,the amount of fungi have an small motion in spring and autumn season in different vegetation,but in summer,the change of the fungi quantity have a big moving,among them the Robinia Pseudoacacia and Prunus armeniaca soil microbial quantity is abundantly.The actinomycetes quantity is abundant in spring and autumn season.In the sample land the tempreture is removing back in spring,but still low.In winter the shed leaves have no decay and the weather is aslo dry,that have some simmar in autumn,which have provide some condition for actinomycetes growth.The fungi quantity is abundant in Caragana korshinskii, Platrhadus orientalis and Farmland.On the aspect of percentage content,bacteria in summer have high content,but the content is different in spring and autumn;The fungi quantity is lowest in summer soil,but relatively have high content in spring and autumn;The actinomycetes quantity is lower in summer,but high content in spring and autumun season.1.2 The amount of soil microbial is distribute differently in soil layer The quantity of soil bactreria and actinomycetes is more in surface layer than the layer of 5-20cm,and have obvious regulation.In three season,the fungi quantity is low in surface layer than 5-20cm in Caragana korshinskii and Robinia Pseudoacacia,but in other vegetation,the fungi quantity is more in surface layer than 5-20cm,so the surface fungi change regulation is obviously than 5-20cm.1.3 The distribution of microbial quantity in different slopeIn the Platrhadus orientalis in spring,the microbial quantity is increase with the decrease of the slope;In Prunus armeniaca in summer and autumn,the microbial quantity is obviously decline with the decrease of the slope;In Caragana korshinskii, Farmland and Medicago sativa L.,the microbial quantity is lower,the regulation is not obviously. In Farmland, Platrhadus orientalis and Medicago sativa L.,the change of fungi quantity and actinomycetes has the simminar regulation trend.The quantity of bacteria and in actinomycetes in Caragana korshinskii has the same regulation trend.2 The soil enzyme acitivity change in different seasonTest the changes regulation of the unease,invertase,hydrogen peroxidase and alkaline phosphatase in different slopes in Desolate land,Farmland,Medicago sativa L.,Caragana korshinskii ,Elaeagnus angustifotia,Prunus armeniaca,Platrhadus orientalis and Robinia Pseudoacacia.2.1 Seasonal change of the soil enzyme activityIn the same vegetation,besides the Desolate land, Elaeagnus angustifotia and Robinia Pseudoacacia,invertase activity in spring season is high in summer and autumn season in the same vegetation;Unease activity have no obvious change in three season;In three season,alkaline phosphatase activity is high in Elaeagnus angustifotia, but in Farmland and Desolate land the enzyme activity is low,in Prunus armeniaca, Robinia Pseudoacacia, Medicago sativa L. Farmland the enzyme activity in summer is higher than the other two season, Elaeagnus angustifotia, Desolate land and Platrhadus orientalis the enzyme activity is higher in autumn than other two season; The hydrogen peroxidase activity is decrease in autumn in Caragana korshinskii and Robinia Pseudoacacia, in Farmland the enzyme activity is higher in summer and autumn than spring,the enzyme activity is no seasonal change in other vegetation.2.2 Slope change of the soil enzyme activityThe unease activity in different vegetation is no obvious changes in different slope, the other enzymes'change is obvious,but have no regulation.