Temporal And Spatial Changes Of NDVI And Its Relationship With Beef And Lamb Production

Vegetation,an important part of terrestrial ecosystems,has many important functions such as climate regulation,biodiversity conservation,and water and soil conservation.Temperature and precipitation are indispensable natural conditions for plant growth and development.The environment of plant growth changes with the change of climate.The change in the growth environment will also affect the growth of the plant.That is to say,climate change is an important factor which affecting the vegetation activity.The vegetation index not only represents the structural information of the surface vegetation,but also reflects the functional information of the surface vegetation.The index is widely used in large-scale ecological remote sensing.Inner Mongolia Autonomous Region is affiliated to the Mongolian Plateau.The research area is rich in products,and has a vast grassland area.It is located in the top five areas in China's pastoral areas.Livestock husbandry has always been a local characteristic industry.Precipitation and temperature in the whole region changed from south to north according to the gradient.Vegetation changes in the study area had a significant response to climate change.Therefore,this paper studied the spatial distribution and change of NDVI in Inner Mongolia Autonomous Region in the past 10 years.The influence of precipitation and temperature on the NDVI of local vegetation was also analyzed.Based on this,the correlation between NDVI and beef and mutton production in the study area was discussed on different spatial and temporal scales.The response of the situation and the impact of NDVI changes on beef and mutton production will be conducive to the healthy development of China's beef and mutton industry.This study used MODIS NDVI data and synoptic meteorological data from 2006 to 2015.Based on remote sensing and GIS related technologies,using SLOPE analysis,correlation analysis,and comparative analyzed the NDVI changes in forest land,grassland,farmland,and other land use in the Inner Mongolia Autonomous Region in the inter-annual and inter-month scales for nearly 10 years in Inner Mongolia.And their response to climate change was also analyzed.On this basis,the relationship between grassland NDVI and the spatial distribution of beef and mutton production in the study area was discussed from the spatial and temporal scales.The results showed that:(1)There are obvious regional differences in NDVI in Inner Mongolia.The overall characteristics of NDVI are declining from east to west.The NDVI changes with the change of the land area in the study area.Among them,the woodland has the highest NDVI,followed by the cultivated land,grassland and other land.Additionally,during the study period,NDVI in Inner Mongolia exhibited an obvious recovering trend,and the increasing rates were as followings: cultivated land > grassland > woodland > other land.Besides,(2)In the past 10 years,the total annual precipitation in Inner Mongolia gradually increased,showing a very significant upward trend(r = 0.60,P <= 0.01);the annual average temperature did not change significantly(P > 0.05).As a whole,in recent 15 years,the precipitation in Inner Mongolia shows an increasing trend,whereas the change of temperature is not obvious.(3)At yearly scale,precipitation played a decisive role in the annual change of NDVI in Inner Mongolia,which means the increase of precipitation promoted the growth of vegetation.At monthly scale,NDVI of vegetation was influenced by both precipitation and temperature.The response of NDVI to precipitation and temperature in grassland and cultivated land all had some time lags,while that of woodland and other land merely showed time lags to temperature.(4)The lamb production in Inner Mongolia is higher than the beef production.Although the specific spatial distribution characteristics are not exactly the same,there is still a certain similarity: The production of beef and mutton in central and eastern area was higher than the average in the study area,while the production of beef and mutton in the southwest was far lower than the average in the study area.Overall,during the period from 2006 to 2015,the beef production in Inner Mongolia increased continuously and showed a very significant increase(r = 0.89,P <= 0.05).The lamb production in the Inner Mongolia Autonomous Region also rose year by year.It also showed a significant increase trend(r=0.92,P <= 0.05).Overall,the output of beef and mutton in the Inner Mongolia has been rising in the past 10 years,and the rising trend is obvious.(5)On the spatial scale,the higher the grassland area in each district,the higher the correlation between beef and mutton production and NDVI,and the correlation with the total NDVI value of the grassland grid in the area is higher than the average value of NDVI.This shows that grassland productivity is not only related to grassland quality,but also directly related to grassland area.The better the grassland quality,the larger the grassland area,the higher the grass production in the region,and the higher the yield of beef and mutton production.In addition,the correlation between the total NDVI value of the grassland grid and lamb production is higher than the correlation with beef production.The analysis on the time scale shows that the correlation coefficient between the NDVI and the yield of beef and mutton in each district and county in the past 10 years is not high.