| Desertification refers to the extreme drought,drought and semiarid and some wet regions of sandy surface conditions,because of the influence of natural factors or human activities,and destroyed the natural fragile ecosystem balance,the sandstorm activities as the main logo,and gradually form the wind erosion and land degradation process of aeolian landform landscape structure,Land desertification is one of the most serious ecological and environmental problems in China.Desertification has affected 18 provinces in China,accounting for about 27 percent of the land area,there are more than 7 million hm2 of land,133 million hm2 of grassland is also deeply affected,in China because of desertification losses as high as 57 billion yuan per year.The Mu Us sandy land is one of the four major sandy lands in China,with fragile ecological environment,serious damage to natural vegetation,serious damage to wind erosion and desertification,land productivity decline,frequent sandstorms,In recent years,the overall ecology of the Mu Us sandy land has improved,and the forest coverage rate has increased from 0.9%at the beginning of the founding of new China to 3.4%.All the mobile dunes have been fixed by manual intervention.It is still necessary to accelerate the forward succession of the sand area ecosystem and realize self-cycling development,and serious impact by desertification.In this paper,the southeast margin of the Mu Us Sandy land is selected as the research area.Through field investigation and experimental analysis,Four typical herbaceous plants were selected,including Stipa bungeana(Stipa capillata Linn),Pipa oxinifer(Cynanchum hancockianum(Maxim.)Al.Iljinski)a,Valva Altai(Heteropappus altaicus(Willd)Novopokr)and Strigomycete(Heteropappus altaicus(Willd)Novopokr)And six typical shrubs such as(Sabina vulgaris Ant.),Artemisia argyi(Artemisia desertorum Spreng.Syst.Veg.),caragana(Amygdalus pedunculata Pall.),Caragana(Caragana intermedia Kuang et H.C.Fu),caragana(Hedysarum mongdicum Turcz Var.),and salix(Salix cheilophila).The physical and chemical properties of soil bulk density,soil moisture,soil organic carbon,soil total carbond soil total nitrogen and soil carbon-nitrogen ratio under these plants were analyzed,and the physical and chemical properties of soil under different plants were studied,so as to provide theoretical basis and scientific methods for desertification vegetation selection,allocation and soil reconditioning in different degrees.The research results show that:(1)the soil physical and chemical properties of four kinds of herbs analysis found that four herbs of soil water content and soil bulk density changes in different depth,different herbs between the change of soil water content and soil bulk density values are also different,rough implicit biggest grass soil moisture content,soil moisture,water retention,strongest Ben's s.grandis,beef heart tastes,altai gowardesh flower soil moisture content,soil moisture,there is no significant difference between water retention,rough implicit son grass more conducive to the accumulation of soil organic matter and the increase of soil fertility,altai gowardesh spend times,Ben's s.grandis and there is no significant difference between beef heart tastes.(2)the soil physical and chemical properties of six kinds of shrubs,found that six kinds of shrubs of soil water content and soil bulk density value changes in different depth,different shrub plants between the change of soil water content and soil bulk density values are also different,caragana korshinskii soil moisture content,the largest hedysarummaxim.There is no significant difference between soil water content and salix,second,thistle,almond,salix,there is no significant difference between soil moisture content,smaller,artemisia sphaerocephala krasch soil water content at least.There was no significant difference in soil water retention between Caragana korshinskii and Artemisia annua,the strongest,followed by caragana korshinskii and Sarcophagus,and there was no significant difference in soil water retention between Caragana korshinskii and Artemisia annua.The changes in the depth of soil chemical composition of six shrub species were different,and the changes in the chemical composition of different shrub plants were also different.Caragana korshinskii was more conducive to the accumulation of soil organic matter and the increase of soil fertility.(3)the herb and shrub plants,soil physical and chemical properties and comparison,the 10 kinds of plants,besides korshinskii and hedysarummaxim.Four kinds of herbaceous plants under the soil moisture content and water retention is greater than the other four shrub plants,caragana korshinskii soil moisture content is greater than the Ben's s.grandis,beef heart tastes and altai gowardesh soil moisture content,hedysarummaxim.Soil water content than beef heart tree and soil moisture content,altai gowardesh spend hedysarummaxim korshinskii and soil bulk density value is far less than the soil bulk density of herbaceous plants,besides korshinskii and hedysarummaxim.Two kinds of shrubs,four kinds of herbaceous plants than the other four shrubs is more advantageous to the soil organic matter accumulation and the increase of soil fertility,Korshinskii soil organic carbon,soil total carbon than Ben's s.grandis,beef heart tastes,altai gowardesh flower of soil organic carbon,soil total carbon,hedysarummaxim.Soil organic carbon,soil total carbon than beef heart tastes,altai gowardesh flower of soil organic carbon,soil total carbon,caragana korshinskii soil total nitrogen is greater than the Ben's s.grandis,cattle heart tastes of total nitrogen in soil.The water content and water retention ability of the soil were the strongest,which was more conducive to the accumulation of soil organic matter and the increase of soil fertility.(4)Correlation analysis of soil physical and chemical properties of different plants showed that there was a certain correlation between the physical and chemical properties of each herb and shrub,and the degree of correlation was also different. |
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