Study On Desertification Dynamic Change And Evaluation Of Desertification Control Tree Species In Changji Hui Autonomous Prefecture, Xinjiang

In this study,by combining field investigation and data collection,the monitoring data of desertified land,soil and water loss status data and overall land use change data of Changji Hui Autonomous Prefecture were sorted and analyzed.Based on NDVI data,the dynamic changes of vegetation,interannual changes of vegetation coverage rate and regional changes of desertification were analyzed and evaluated.Ahp,index and method were used to analyze and evaluate the suitability of different desertification control tree species.The main results were as follows:(1)Desertification and its control status:In 2014,the desertified land area of Changji Prefecture totaled 27,300 km~2,accounting for 36.9%of the total area of Changji Prefecture.Qitai County had the largest desertified land area,while Muli County had the smallest.The total desertified land area of Changji Prefecture decreased by 416.93km~2in 2014 compared with that in 2009.In 2014,the area of soil and water loss in Changji Prefecture was 70,200 km~2,with the largest area of soil and water loss in Muli County and the smallest in Hutubi County.Compared with 2009,the area of soil erosion in Changji Prefecture increased by 327.82km~2in 2014.Compared with the current land use data of Changji Prefecture in 2009,2014 and 2019,the desert area decreased significantly,with a total reduction of 7.97%.Woodland area showed a continuous growth trend,with a total increase of 6.77%.(2)Desertification comprehensive assessment:Vegetation growth in Changji Prefecture showed a trend of improvement from 2000 to 2019,and the area of low-cover vegetation in Changji Prefecture was the largest,accounting for 45.09%of the total area.The proportion of medium-cover vegetation and high-cover vegetation was 20.70%and 22.69%,respectively.The proportion of vegetation area with higher coverage was 11.13%.The average proportion of unvegetated area was 0.39%.In Changji Prefecture,the area of mild desert area is gradually decreasing,and the area of moderate desertification area has a small fluctuation range,and the annual change trend is not obvious.The area of non-desertification area fluctuated greatly,and the annual change showed an increasing trend.From 2010 to 2015,the area of severe desertification increased significantly,mainly concentrated in Jimsar County,Qitai County,and the northern plain area of Mulei Kazakh Autonomous County.From the perspective of location and time,the main reason was the construction and development of Xinjiang Jundong Economic and Technological Development Zone since 2010.Construction of industrial facilities,park construction,coal mining,road network construction and so on increased the construction land and reduced the vegetation coverage,but the area of severe desertification showed a decreasing trend from 2015 to 2019.Overall,the desertification control work in Changji Prefecture has achieved good results.(3)Selection and evaluation of tree species for desertification control:It is suggested to select Ammodendron ammodendron,Jujube sand jujube,Tamarix ramosissima,Populus euphratica,Lycium ruthenicum and sea buckthorn as the preferred tree species in moderate and above desertification areas,and it is suggested to select white ash,white Elm,Poplar Xinjiang and Lycium ruthenicum Ningxia as the preferred tree species in mild and below desertification areas.The tree species with high score in sheltershelter forest are Ammodendron ammodendron,jujube sand,ash,Tamarix ramosissima,white elm,Populus euphratica and Populus sinkiang.It is suggested to choose Ammodendron Ammodendron,jujube sand,ash and Tamarix ramosissima in the top of the list,which has strong ecological adaptability and excellent performance in wind break and sand consolidation.The tree species with high scores in the economic forest were Ammodendron ammodendron inoculated with Cistanche deserticola,Lycium barbarum Ningxia,Lycium barbarum black fruit,Seabuckthorn,jujube macrophylla,Fructus officinalis and grape.It is suggested that ammodendron ammodendron inoculated with Cistanche deserticola,Lycium barbarum Ningxia and Seabuckthorn should be the main planting species in the northern desert region.