Spatiotemporal Variation Characteristics And Environmental Response Of Meadow Grassland Condition In Northern Songnen Plain

Grassland is an important barrier to protect terrestrial ecosystems.As the basis of energy flow and material circulation,the basic condition of grassland is an important indicator of the healthy and sustainable development of grassland.Meadow grassland is one of the important grassland types in Songnen Plain,and is an important basis for livestock production in Songnen Plain.In order to explore the temporal-spatial variation characteristics and environmental response of the meadow grassland in northern Songnen,this paper took the natural meadow grassland in Zhaodong,Lanxi and Anda as the research objects,and conducted field surveys in the study area in April and September 2019,April and November 2020 respectively,combined with the collected data.Through the analysis of natural indicators(soil quality,vegetation coverage,meteorological data,etc.)and the statistical analysis of social and economic indicators(economic density,per capita agricultural,forestry,animal husbandry and fishery yield,land use,etc.)to quantitatively depict the temporal-spatial variation characteristics of grassland basic conditions and grassland health status.Obtaining measured data through experiments,consulting statistical data,and obtaining remote sensing data through official release channels,principal component analysis and analytic hierarchy process were used to reduce dimension and give weight to three principal components of soil quality,land use and vegetation cover to evaluate grassland base condition.Grassland is known as the "skin of the earth".It has various ecological functions such as climate regulation,water conservation,sand fixation,windbreak and soil and water conservation,and environmental protection.As the basis of energy flow and material circulation of terrestrial ecosystem,it is not only the food source of herbivorous livestock,but also the root of animal husbandry production.The range condition of the grassland can be understood as the health condition of the grassland,and its quality is assessed according to the land and vegetation condition of the grassland.In the field of environmental science research,people pay more attention to the agricultural ecological environment and urban environment,less for grassland environmental health research,which makes the grass base condition evaluation system is different in practice,it is difficult to transverse systematically contrast the response law of grass base conditions,to some extent hindered people to make effective judgment on the status of grassland,and affect the management and utilization of grassland.The Songnen Grassland is located in the northeast of China,and the Songnen Plain is formed by the alluvial and flood accumulation of Heilongjiang River,Nenjiang River and their tributaries.To understand the spatiotemporal variation characteristics of northern meadow grassland and their response,Taking the natural meadow grassland in Zhaodong City,Lanxi County and Anda City,After consulting the relevant literature and conducting the field investigation,The physiochemical properties of soil,soil nutrients and land use were studied quantitatively,Then,through the principal component analysis method,hierarchical analysis method and other analysis methods,Using experiments to obtain measured data,consulting for statistical data,obtaining remote sensing data through official release channels,Through quantitative comprehensive analysis of three principal components,including soil quality,land use and vegetation cover,By calculating the principal component factor weights and the composite score,It can be observed that the highest composite score in Lanxi County between2019–2020,Next to Anda,Finally,in Zhaodong,It shows that the grassland base condition of Lanxi is of the best quality,Anda and Zhaodong are slightly inferior,Comparing the combined scores for 2019 and 2020,Grassland base condition is developing in a good direction under the correct guidance of the government.In terms of the analysis results of the response,the ecological environment of the three research areas has a significant change trend,indicating that the ecological environment of each region has been actively improved under the relevant protection measures.Among them,the grassland ecological quality change of Zhaodong city recovered the fastest,followed by Anda City,and Lanxi County recovered the slowest.The main influencing factors of the base condition change of the grassland system in recent years are clarified to provide reference for strengthening the grassland ecological construction and protection in the northern region of Songnen Plain.