Traits And Influencing Factors Of Rainfall Redistribution Of Three Typical Shrubs Canopy In The Mu Us Sandy Land

Rainfall redistribution in the canopy,especially the stemflow enrichment effect,is an ecological process mechanism for xerophyte shrubs to adapt to arid habitats.The study of the process and pattern of rainfall redistribution in the canopy of typical shrubs in the Mu Us sandy land(Hedysarum mongolicum,Caragana intermedia and Artemisia ordosica)has important theoretical significance for elucidating the ecological and hydrological mechanism of shrub pattern maintenance under the background of soil drought.Rainfall characteristics and morphological factors are the key factors that determine canopy rainfall redistribution and enrichment efficiency.The rain redistribution pattern and its influencing factors of the canopy of different species of shrubs,the stemflow and its collection rate of rainwater,and the influence of soil moisture were carried out respectively.The main research results and conclusions are as follows:1.Rainfall redistribution of three types of shrubsBy observing the redistribution phenomenon of rainfall by typical shrubs in the Mu Us sandy land(Hedysarum mongolicum,Caragana intermedia and Artemisia ordosica),the redistribution characteristics of the three shrubs under different rainfall and intensity were analyzed,To compare the adjustment effects of different shrubs in the redistribution of rainfall.The results showed that::(1)During the test period,the area monitored 26 times of rainfall,with a total rainfall of 280.9 mm;(2)Cumulative stem flow rates of Hedysarum mongolicum,Caragana intermedia and Artemisia ordosica shrubs were 11.1%,8.5%,and 7.2%,the penetration rain rate was 80.7%,79.8%,and 75.3%,and the interception rate was 8.2%,11.7%and 17.7%;(3)Under different rainfall amounts and rain intensities,the stem flow,stemflow rates,penetration and penetration rate of shrubs are shown as follows:Hedysarum mongolicum is higher than Caragana intermedia,Caragana intermedius is higher than Artemisia ordosica,the interception amount and the interception rates are shown as follows:Artemisia ordosica is higher than Caragana intermedia,and Caragana intermedia is higher than Hedysarum mongolicum.2.Factors affecting rainfall redistribution pattern of three shrubsThe maximum rainfall intensity of 10 min is positively correlated with the stem flow and stem flow rate of the three shrubs(P<0.05);it has a power function extremely significant positive correlation with the penetration and penetration rate(P<0.001),and the interception were all showed a significant positive correlation with the power function(P<0.05),and a negative correlation with a power function(P<0.05)with the interception rate;Hedysarum mongolicum,Caragana intermedia and Artemisia ordosica produced penetrating and stemflow The rainfall thresholds are 1.37mm,1.41mm and 1.91mm,2.39mm,2.53mm and 2.55mm,respectively.There was a significant positive correlation between the interception of Hedysarum mongolicum’s interception and the number of branches and leaf area index(P<0.001),and a significant negative correlation with the plant height and crown area(P<0.05).The stemflow of Caragana intermedia’s stemflow had a very significant negative correlation with the branch inclination angle of shrubs(P<0.01),and a very significant positive correlation with the leaf area index(P<0.001).The interception was related to the shrub’s inclination.The branch inclination showed a very significant positive correlation(P<0.001).The stemflow of Artemisia ordosica was significantly positively correlated with the inclination of the shrubs(P<0.05),and the penetration was significantly negatively correlated with the base area of the shrubs(P<0.001).There was a significant positive correlation between interception and shrub crown area(P<0.01).3.The enrichment effect of three shrubs stem flow on rainwaterDuring the observation period,the confluence rates of Hedysarum mongolicum,Caragana intermedia and Artemisia ordosica shrubs were 288.58,200.33 and 44.62,respectively.Both have a very significant positive logarithmic function relationship with rainfall and rainfall intensity(P<0.001).There is a very significant negative correlation between the rainwater collection rate of sheep wood shrubs,the crown area of the shrubs and the area of the shrub base(P<0.001),and there is a significant positive correlation with the number of branches(P<0.001).The rainwater collection rate of Caragana intermedia was significantly negatively correlated with the crown area,branch inclination angle,leaf area index,branch length and base area of the shrub(P<0.05).The rainwater collection rate of the stem flow of Artemisia ordosica shrubs was significantly negatively correlated with the leaf area index of the shrubs(P<0.05).Through the dynamic monitoring of the soil moisture in the base,middle and outer parts of each shrub,the results showed that the stemflow of Fusarium vulgars,Caragana intermedia and Artemisia ordosica shrubs all have the function of replenishing soil moisture,and 6h after rain,the same shrub canopy is under the canopy.The depth of the wet front in the rhizosphere is greater than that of the lower and outer canopy,and the soil moisture content of Yangchai and Caragana intermedia is about twice that of bare sand.The influencing factors of the redistribution pattern of rainfall canopy of different shrubs in the Mu Us Sandy Land are significantly different.Both the morphological structure and rainfall pattern will affect the redistribution pattern of the shrubs,and also affect the shrub confluence rate.Study the rainfall of typical shrubs in the Mu Us Sandy Land The characteristics of canopy redistribution and its influencing factors have an important impact on balancing the ecological functions and productivity of deserts.