Study On The Nutrient Accumulation Characteristics Of Meadow Wetland In Yinchuan Plain

Wetland ecosystem is one of the most important ecosystems on earth,and the ecological value is very high.In most of the arid and semi-arid wetland studies,meadows are often regarded as wetland types of over-wet soil.Based on the development history of oasis in Yinchuan Plain,this paper divided the meadow wetland into three developmental types,that is type I meadow wetland in the ditch slope area,type II meadow wetland located in the low temperature depression of the canal,type?located at the edge of the tail lakemeadow wetland,and selected the type IV as a contrast,which is beach wetland cultivated and abandoned by human.All these four wetland types are distributed in 10 sample plots,and all the types are also used to represent the different stages of meadow wetland development in Yinchuan Plain.The way of space instead of time accumulation study on random can be used to reveal the nutrient characteristics and their accumulation in different developmental stages of meadow wetland in Yinchuan Plain.Before the research,in order to obtain the soil and vegetation data,a total of 57 sample plots of various meadow wetlands in Yinchuan Plain had been randomly chosen to be used in grasping the Characteristics of Nutrient accumulation from space in Meadow Wetland of Yinchuan Plain.In this study,from the aspects of community and soil,we selects the method of combining field investigation with laboratory analysis to study the nutrient characteristics and soil particle size of soil and community in the meadow wetland of Yinchuan Plain,and then further makes the soil quality model,so that provides reference for evaluating the spatial characteristics of soil quality in meadow wetland of Yinchuan Plain.The study of the community is carried out from the aspects of community and plant ecological chemistry,and finally the soil quality index is coupled with plant community index and nutrient index in order to reveal its inherent association mechanism.The accumulation of nutrient in different wetland wetlands chosen in sample plots is studied by using the method of space instead of time.The main conclusions are as follows:1)The average level of carbon and nitrogen and phosphorus in the plant community of meadow wetland in Yinchuan Plain is lower than that of the global plant community.The ground contents of carbon and nitrogen and phosphorus are above the underground part.However,combining with the data of vegetation root/shoot ratio,it shows the underground part is still the main place where the nutrient elements of the ecosystem type are stored and accumulated.2)In the vertical direction of meadow soil,the trend of soil nutrient in the research area is generally decreased with the increase of soil depth.However,due to the special fertility and inoculation process of meadow wetland,organic carbon,total nitrogen,available nitrogen will appear in the 20-40cm or so high value.The content of available N is consistent with the change trend of organic carbon and total nitrogen,and the change of available phosphorus is consistent with the change of total phosphorus.3)In the selected four groups of typical meadow wetlands,the nutrient of type ? to type ? shows an increasing tendency,and the nutrient indexes of type ? is at the lowest level,and the grain size is becoming more and more fine.The type I with the most coarse soil particles are not conducive to nutrient retention.4)According to the score of soil quality comprehensive model and the figure of soil quality drawn by the soil nutrient index in the study area,it is found that the comprehensive soil quality of Yinchuan Plain shows the trend of east high west low and north high south low,total phosphorus content is west high and east low.5)The results of RDA analysis shows that the effect of each index on plant community characteristics is AK>TP>TN>coarse sand>pH>viscose>SOC>AN>TDS>AP;the contribution rate of available potassium is the highest.6)Summarize the general characteristics of four types of meadow wetlands,and found that soil type ? is low in soil nutrient and coarse in grain,which is not conducive to accumulate.The soils of type? has high soil texture,high nutrient accumulation,low plant carbon and nitrogen content.The type?soil is obviously gleyization and waterloggogenic and has a clear carbon layer.The IV type has high salt,fine grain,and is a poor quality grassland with single type vegetation.After years of cultivation,The ? type meadow is not suitable for farming,but type ? is among the four categories which are most beneficial to the accumulation of nutrients.Later stage,we can consider rational use of type @meadow wetland.