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Université de Mongolie-Intérieure (2020)

Desertification Evolution,Restoration Assessment of Aerial Seeding and Impact of Desertification on Ecosystem Services in Mu Us Desert

刘庆福;

Titre : Desertification Evolution,Restoration Assessment of Aerial Seeding and Impact of Desertification on Ecosystem Services in Mu Us Desert

Auteur : 刘庆福;

Grade : Doctoral Dissertation 2020

Université : Université de Mongolie-Intérieure

Résumé partiel
Desertification is the main cause of ecosystem degradation in many regions and one of the major environmental,social-economic problems facing the world.Desertification seriously erodes land resources and further affects the sustainable development of agriculture,animal husbandry and even economy.According to the "Ordos Declaration" issued by the 13 th Conference of the Parties in Ordos in 2017,the "United Nations Convention to Combat Desertification" pointed out that desertification is one of the main challenges that hinder global sustainable development,and it seriously threatens the ecosystem’s ability to provide benefits to society.The Mu Us Desert is located in the transitional area from the Ordos Plateau to the Loess Plateau,and is a typical eco-environmental fragile area where agriculture,animal husbandry and forest interlace.With the development of agriculture and animal husbandry,energy development,and implementation of regional policy measures in the Mu Us Desert,the desertification situation and ecological environment have undergone significant changes in recent years.Therefore,exploring the impact of desertification on ecosystem services and assessing the effects of aerial seeding restoration from 1986 to 2015 can provide a theoretical basis for desertification prevention and control in the Mu Us Desert.In this study,the Mu Us Desert was used as the study area.Based on the measured data of vegetation coverage in 71 field sites,10 desertification remote sensing monitoring indexes were tested,and the most suitable index was selected for this area ;and then the desertification dynamics in seven periods from 1986 to 2015 in the Mu Us Desert were inversed from the whole-desert scale and provincial scale.Based on the meteorological data,socio-economic data and policy investment data,the driving factors of the desertification change during this period were analyzed.Further more,based on the vegetation and soil samples from 32 aerial seeding restoration sites in Mu Us Desert,vegetation diversity,soil microbial diversity and soil multifunctionality were obtained through high-throughput sequencing and experimental test,and the effect of aerial seeding restoration was evaluated from three aspects : vegetation,soil microorganism and soil multifunctionality,and the driving factors and driving mode of soil multifunctionality were defined.Finally,based on remote sensing data,meteorological data and socio-economic data,the spatial quantification of ecosystem services in the Mu Us Desert was carried out,and the impact of desertification on ecosystem services was analyzed.The results are followed :(1)Among the 10 desertification remote sensing monitoring indexes selected through literature summary,the indexes reflecting the surface energy information and vegetation information have high accuracy for the desertification inversion.The Desertification Difference Index(DDI)not only reflects the surface radiation characteristics but also includes vegetation information,and has clear biophysical significance,can reflect the changes of surface coverage,water-heat combination and land desertification,and is the best remote sensing monitoring index of desertification in Mu Us Desert.(2)The overall desertification spatial pattern dynamics in the Mu Us Desert during the past 30 years showed a reversal trend in the central and eastern regions,and recovery and intensification occurred alternately in the western regions.From 1986 to 2015,the process of desertification at the whole-desert scale showed a trend of first deteriorating and then reversing.It continued to intensify from 1986 to 2005,and the area of heavily and severely desertified land increased during the process.After 2005,desertification gradually reversed,and the area of heavily desertified land decreased significantly,but until 2015,the desertification degree of whole-desert scale was still higher than that of 1986 ;the desertification process has a strong spatial heterogeneity at the provincial scale.Among them,the most obvious restoration of desertification is the five districts and counties in Shaanxi Province,which continued to reverse after 2000 ;

Mots clés : Remote sensing monitoring; Desertification dynamics; Driving factors; Aerial seeding; Soil microbe; Ecosystem services;

Présentation (CNKI)

Page publiée le 23 octobre 2020