| The loess region of Northern Shaanxi 1s one of the difficult site areas in China,with few rainfalls and a large amount of evaporation,Vegetation reconstruction 1s an effective way to improve the ecological environment in this area and increase the benefit of the forest ecosystem in this area.The distribution of slope micro-topography in the Loess Plateau area is widely distributed,in the process of artificial cultivation on the slope scale,the difference between micro terrain caused by micro-topography should be considered and then the vegetation coverage of the region should be improved.Therefore,in this paper,we choosed shallow gully,collapse,gully,slope and scarp of Wuqi County in Shaanxi Province as the research object.Analyzed soil moisture characteristics and stand structure of micro-topography,provided a scientific basis for vegetation distribution in this area,realized the local idea of near-natural afforestation and improved the stability of the ecosystem.Through investigation and research,the conclusion of this paper is as follows:(1)During the detection period of all year and growing season,the soil water content in the soil layer of 0-160cm was increased with the increase of depth.The soil had the highest water content in the gully,scarp is the lowest.There was a significant positive autocorrelation in soil moisture in each soil layer,the variation trend of soil moisture in the 5 types of micro-topography were not significant during the detection period.The soil moisture in the collapse had a tendency to increase weakly in each soil layer,the variation trend of soil moisture in the other 4 kinds of micro-topography increased and decreased in each soil layer.There are also differences in the rate of change of 5 micro terrain during the observation period,such as slow platform,collapse,scarp,gully and shallow gully.The quickest rate of soil moisture change in the collapse is the fastest.(2)The soil water content of micro-topography is different from that of the original slope.There was a significant difference between the soil moisture of the platform,the collapse,the scarp and the gully.On the whole,the soil moisture in the micro terrain decreased first and then increased in the 0-10 meters soil layer.And the variation of soil moisture in the 0-5 meters soil layer is large,a small change in the 5-10 meters soil layer.In the 0-1 meters soil layer,there were no dryness in five kinds of micro-topography.In the 1-10 meters soil layer,different degrees of dryness have appeared in different micro-topography.(3)The area of the micro terrain on the slope of the study area accounted for 24.96%of the total area of the slope.The number and area from large to small is gully>collapse>shallow gully>platform>scarp.The micro-topography in the number of species,the number of arbor and stand density were greater than the original slope.The average stand density of plant communities on five types of micro-topography from large to small is gully>platform>shallow>collapse>scarp.The average DBH and average tree height of the trees was arbor which growing on the shallow gully.The trees which grows on the slow platform,gully and collapse were concentrated in small diameter wood and middle lower layer of trees.In the five kinds of micro terrain,Simon poplar height and DBH values were higher than those of other species.For Robinia pseudoacacia,the diameter of the DBH was higher in the shallow gully,and the height of the tree growing on the gully was the largest.The growth status of apricot in the shallow gully was the highest.Simon plant growths on the slow platform was the best. |
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