Spatial And Temporal Distribution And Their Correlations Of Organic Matter And Total Nitrogen In The Sediments Of Liaohe Estuary

Wetland is the transitional zone between terrestrial ecosystems and aquatic ecosystems.It plays an important role in regulating the environment and plays an irreplaceable role in maintaining ecosystem balance and ensuring sustainable development of ecosystems.Wetland is not only an important destination of terrestrial matter,but also a natural barrier for purifying pollutants and retaining natural resources(Chen Hua 2006,Nedwell DB etal.1996,and Lu Xiaofeng 2015).In order to study the content of nutrients in estuarine wetland,we study the continuous change process of organic matter(OM)and total nitrogen(TN)in reed wetland sediments with the growth period of reeds,and the spatial change rules,and explore the internal relationship between OM and TN content.Through the analysis,the wetland can be rationally developed and used to protect the wetland from eutrophication and nutrient loss.In this paper,the contents of OM and TN are analyzed from statistical and mathematical models.It is different between different time and space of OM and TN contents in sediments.Levene test is used to test the homogeneity of data,and single factor ANOVA is used to test the difference.In this paper,Pearson test was used to analyze the correlation between OM and TN contents in sediments.It was done to analyze OM and TN content by linear regression model.In this paper,the spatio-temporal analysis and correlation analysis of OM and TN content were analyzed.The results showed that:At the time of change,during reed Germination period(April,May),the OM content increases in the sediments,During Vegetative development period of reed(May,June and July),the content of OM has little difference.During reed reproductive period(July,August and September),the content of OM first descends and then rises.During reed maturity period(September,October),the content of OM is decreasing.From the functional area,the content of OM in the experimentation area is higher than that in the buffer zone,and the content of OM in the buffer zone is higher than that in the core area.The fluctuation of OM content in the experimentation area and the buffer zone is large,and the volatility of OM content in the core area is relatively small.The change in space vertically,the content of OM in April on the far river has little difference.In May,June,September,and October,the surface sediment obtains maximum content at 0-10 cm depth,and the difference is not obvious at the other depth.The OM content has minimum value in August and July at the 0-10 cm depth below the surface,and it reaches the maximum value at 20-30 cm depth.Near the river,the OM content has little difference in May and April,and it obtains the maximum value in June,July,August,September,and October at 20-40 cm depth,and The OM content has little difference at the other depth.Experimentation area(Fr1,Fr2,Nr1 and Nr2),buffer area(Fr3,Fr4,Nr4,Nr5),core area(Fr5,Fr7,Fr8,Fr8,Fr7,and)have significant linear correlation at all depths.However,the linear correlation of the depth of OM at the Fr6 sampling point is not significant.In the horizontal space,the content of OM in the boundary of the experimentation area and the buffer zone is higher,and the difference of the OM content in the other regions is not significant.In the time change,when the reed Germinated(April and May),the TN content in the sediment increases,and during the vegetative growth period of reed(May,June,and July),the TN content in the sediments increases first and then decreases.During reed mature period(September,October),the TN content in sediments is almost unchanged far the river.During reed maturity period(September,October),the content of TN in sediments increases dramatically,and it reaches the maximum value in October.From the functional area to anlyse,the content of TN in the experimentation area is higher than that in the buffer zone,and the content of TN in the buffer zone is higher than that in the core area.The fluctuation of TN content is large in the experimentation area and buffer zone,and the fluctuation of TN content is relatively small in the core area.The change in space vertically,the TN content is higher in the depth of 20-30 cm in April far the River,and the TN content changes little in other depth.During May,June,July,August,October,the content of TN reaches the maximum value.The content of TN reached the maximum value at the depth of 30-40 cm depth in the surface depth of 0-30 cm in September,and the other depth has little difference.Near the river zone,the TN content reaches the maximum value at the depth of 0-10 cm in May and April.During September and October,the content of TN reaches the maximum value in the depth of 10-20 and 20-30 cm.During the June,July and August,the TN content obtains maximum value at the depth of 30-40 cm and 40-50 cm and it has little difference in other depth.At Experimentation area(Fr1,Fr2,Nr1 and Nr2),buffer area(Fr3,Fr4,Nr4,Nr5),and core area(Nr5,Nr6,Nr7,Nr8,Fr5,Fr6,Fr7,Fr8),The TN contents have significant linear correlation at all depths.In the horizontal space,the content of TN in the boundary of the experimentation area and the buffer zone is higher,and the difference in the content of the TN is not significant in the other regions.Through the regression analysis of the content of OM and TN: there is a significant negative correlation between the OM and TN content during June.At April(Fr),May(Fr,Nr),July(Fr,Nr),August(Nr),September(Fr,Nr),October(Fr and Nr),there was a significant positive correlation between the content of OM and TN in sediment.Far and near the River,The linear correlation between OM and TN content in the sediment was not significant during August and April.The study on the temporal and spatial variation of OM and TN content and the correlation between OM and TN content in Liaohe estuarine wetland provide effective data for the source of OM and TN in wetland sediments.The changes in the content of OM and TN in the sediments are influenced by human factors,such as river runoff,biological,temperature,and microbial effects.Through studying the changes of OM and TN,we can explore the source of the problem,and provide reliable scientific basis for the study of wetland eutrophication and other ecological problems,and promote the research of pollutants purification in estuarine wetland sediments.