Disturbing Effects Of Shifting Cultivation On Regional Land Use

Shifting cultivation is one of the main causes of forest degradation,and the stress on land resources and regional ecological environment is becoming increasingly prominent.By exploring the impact of shifting cultivation on regional land use,it is an important entry point to recognize the impact of traditional agriculture on the continuous use of land in the process of evolution and development,and it is of great practical significance to seek a mitigation path for the ecological problems of shifting cultivation and promote the improvement and development of the theory of global shifting cultivation research.The paper takes the border areas of China,Vietnam,Laos,Thailand,and Myanmar as the study area,through identification and analysis of the occurrence process of shifting cultivation,to quantify the relation between shifting cultivation and its disturbed area,and to reflect its influence on land use types and landscapes pattern change of the whole study area,so as to reveals the impact of shifting cultivation on land use change,and provides theoretical and methodological basis for formulating cross-regional differentiated land use management countermeasures.The main research conclusions are as follows:(1)It is a feasible path to realize the identification of shifting cultivation by calling the LandTrendr algorithm based on the Google Earth Engine platform.Both the Normalized Vegetation Index(NDVI)and the Normalized Burn Ratio(NBR)used in the study can monitor the long-term sequence of land-use unit vegetation cover,but NBR has a better recognition effect on the threshold and inflection point of vegetation coverage in the process of shifting cultivation.Shifting cultivation is widely distributed in the study area,mainly in the central and western regions.It is not only spatially distributed but also has obvious continuity in occurrence time.The occurrence time is often relatively close of shifting cultivation in adjacent areas.(2)Regional land use is obviously affected by the disturbance of shifting cultivation.Judging from the spatial distribution of the disturbed area of shifting cultivation,it is mainly distributed around the shifting cultivation.The degree of disturbance is weakened with the increase of the distance.Distance is not more than 100 m between shifting cultivation area and majority disturbed land use units.Disturbance on land use type by shifting cultivation is mainly manifested that primary forests,secondary forests,cropland and other shifting cultivation related land use types with a high cumulative land change rate in this area.At the same time,land use types changes frequency of adjacent land use units also has a significant aggregation effect.The effect of the restructuring and disturbance of the shifting cultivation on landscape pattern is concentrated on the damage to the integrity of regional patches.(3)The shifting cultivation and its disturbance to land use are different in different countries.The probability of occurrence of shifting cultivation in China,Vietnam,Laos,Thailand,and Myanmar in the study area is 7.5%,5%,8%,9%,and 13%,respectively.However,it did not bring a simple positive correlation in probability of disturbed by shifting cultivation,the frequency of regional land use changes and the disturbance on landscape pattern.As far as land use is concerned,study area has significant changes in land use types,prominent land waste,and deterioration of land quality.These are all closely related to shifting cultivation.It should be promoted that land use development strategies based on shifting cultivation of the ecology,capital management,and coordinated development.