The Clonal Growth Of Hedysarum Mongolicum And Its Water Physiological Effects Under Different Habitats In The Mu Us Sandy Land

In order to study the distribution of Hedysarum mongolicum under the heterogeneous pattern of soil moisture in the southwestern edge of the Mu Us Sandy Land and the water integration characteristics and physiological effects of Hedysarum mongolicum cloned mother and son ramets in different habitats.In this study,the artificial seedling of Hedysarum mongolicum shrubs in the southwestern edge of Mu Us was studied under three habitats(MWSD:Hedysarum mongolicum cloned mother ramet was in a high water and son ramet was in a low water environment,MDSW:Hedysarum mongolicum cloned mother ramet was in a low water and son ramet in a high water environment,MDSD:Hedysarum mongolicum cloned mother ramet and son ramet are all in low water environment).In this study,we combined with field investigation,acid fuchsin marker tracing,stable isotope technology,physiological and ecological monitoring and other methods to study the heterogeneous pattern of Hedysarum mongolicum in the Mu Us sandy land at multiple scales The main research results of the water clonal integration characteristics of Hedysarum mongolicum are as follows:1.The soil moisture in Mu Us sandy land has temporal and spatial heterogeneity.A total of 12 "highmoisture centers" and "low-moisture centers" were monitored in the soil moisture in the study area between 3.9-76.3 m and the different moisture centers were distributed irregularly.Clonal propagation under the heterogeneous distribution of soil moisture at habitat scale is a key factor affecting the distribution of Hedysarum mongolicum.Under the heterogeneous distribution of soil moisture,the generation scale(3.3-3.8 m)of the spatial autocorrelation that controls the overall spatial variability of the Hedysarum mongolicum is consistent with the spatial range of the clonal propagation rhizome(0.823.83 m).The highest spatial autocorrelation degree of the spherical fitting equation reaches 0.966.2.The order of the transportation range in the four different treatments in the water heterogeneous habitat:MWSD(M)>MDSW(M)>MDSW(S)>MWSD(S).In the MWSD(M)treatment in a water heterogeneous habitat,the transport rate of the mother ramet to the son ramet>the mother ramet self-transportation rate;in the MWSD(S)treatment,the cloned son ramet self-transportation rate>the son ramet to mother ramet transport rate;in the MDSW(M)treatment,the self-transportation rate of the cloned mother ramet>the transportation rate of the mother ramet to the son ramet;in the MDSW(S)treatment,the self-transportation rate of the cloned son ramet>the transportation rate of the son ramet to the mother ramet.The order of the transportation range of the two treatments in the waterconsistent habitat:MDSD(M)>MDSD(S).In the MDSD(M)treatment,the self-transportation rate>the transport rate of the mother ramet to the son ramet;in the MDSD(S)treatment,the cloned son ramet only get out self-transportation.3.The order of the physiological and ecological indexes of the cloned mother ramet in three different habitats is:MWSD>MDSW>MDSD,and the order of the physiological and ecological indexes of the cloned son ramet is:MDSW>MWSD>MDSD.The relative water content,initial specific conductivity,photosynthetic rate,stomatal conductance,transpiration rate,initial fluorescence and other physiological and ecological indicators of cloned ramets increased with the increase of soil moisture,and there was a significant correlation between different habitats(P<0.05).In the same habitat,the relative water content,initial specific conductivity,maximum specific conductivity,photosynthetic rate,stomatal conductance,transpiration rate,initial fluorescence,maximum fluorescence,variable fluorescence,The original light energy conversion rate and potential PSII activity were both greater than the physiological and ecological index values of cloned ramets under low-moisture patches.4.In the same habitat,the hydrogen and oxygen isotopes of Hedysarum mongolicum before and after root cutting are different.The analysis of water sources shows that the cloned son and mother ramets used different soil moisture levels before and after root cutting.In the MWSD habitat,the level of soil moisture used by the cloned mother ramet after root cutting is basically unchanged,and the son ramet use deeper soil water(from 20-50 cm to 50-150 cm);in the MDSw habitat,the cloned mother plant uses the soil water after the root is broken.For deeper soil water(from 20-50 cm to 50-150 cm),the son ramets prefer to use shallow soil water(20-50 cm).5.In the three different habitats,the self-transport rate of the cloned parent ramet was positively correlated with water-related physiological indicators,and the self-transport rate was significantly positively correlated with the stomatal conductance and variable fluorescence of the cloned ramet;The transport rate is significantly negatively correlated with the photosynthetic rate and transpiration rate of the cloned parent ramet,and significantly positively correlated with the relative water content,photosynthetic rate,and variable fluorescence of the cloned son ramet;the transport rate from the cloned son ramet to the mother ramet is significantly correlated with the cloned mother ramet.The transpiration rate and stomata conductance of the plant were significantly positively correlated,and were significantly negatively correlated with the net photosynthetic rate and transpiration rate of the cloned progeny.