Study On Improvement Effect Of Artificial Poplar Forest On Saline Alkali Soil In Panjin

The saline-alkali land in Panjin is a typical coastal saline-alkali land.The salinization of coastal areas is different from the traditional inland saline-alkali land index,and further research is needed.As a main measure of soil improvement,artificial construction of shelter forests has the advantages of high economic and ecological benefits,saving fresh water,long time effect,and wide application area.In the process of planting plantations,soil moisture,nutrient conditions and climate factors will be improved with the restoration of vegetation,and the constantly changing environmental ecology will in turn affect the evolution of forest vegetation community types.This article uses a combination of investigation and experiment to investigate the geology,climate,hydrology and other factors of Panjin area,and briefly analyze the reasons for the formation of coastal saline soil.After investigating and analyzing the types of artificial forests on saline-alkali land in Panjin area,different types of pure artificial poplar forests(including Populus euphratica,Populus alba,Populus tomentosa,Populus silver,Populus Liaoning)were selected as experimental objects to compare the microclimate indicators inside and outside each poplar forest.At the same time,using reed land and blank bare land soil as a reference,through experiments,the contents of nitrogen,phosphorus,potassium,salt and organic matter in the soil of each sampling point were analyzed to explore the soil characteristics of the saline-alkali land in Panjin,and by comparing the water and salt of different tree species in the artificial poplar forest soil.Analyze the impact of poplar forest on the water-salt status of saline-alkali land and discuss the relationship between water and salt.By investigating the diversity of herbaceous plants under each poplar forest,analyze the role and reason of each artificial poplar forest in restoring biodiversity.The main research results obtained in the experiment are as follows:(1)All five artificial poplar forests can adjust the air temperature and humidity to varying degrees.It shows that humans can improve the local microclimate to varying degrees through certain engineering and technical measures.In this experiment,Populus tomentosa forest has the most significant effect on air temperature cooling in the forest,and Populus alba has a significant effect on air humidity and soil temperature.(2)Panjin saline-alkali soil is characterized by low total nitrogen and phosphorus content,available phosphorus,available nitrogen and other elements content are significantly lower than the growth requirements of ordinary plants,and soil nutrients are not balanced.The pH is alkaline,and the total salt content is high.It is an obvious saline-alkali soil.Artificial poplar forest can adjust the soil water content and salt content of saline-alkali land,improve the soil water and salt status,and play a positive role in the improvement of saline-alkali land.The ability of each tree species to adjust soil water content in the order of Populus tomentosa>Populus alba>Populus Liaoning>Populus euphratica>Populus silver.The order of the ability to reduce the salt content of the forest stands is:Populus tomentosa>Populus Liaoning>Populus alba>Populus euphratica>Populus silver.Analysis shows that there is a significant positive correlation between total soil salt and soil water content,reflecting the characteristics of "salt follows water and salt follows water".(3)Through the investigation of understory herbaceous vegetation diversity,the results show that planting artificial forests can increase vegetation diversity.In this experiment,the species of vegetation in the Populus tomentosa forest is the most abundant.There were 16figures,15 tables and 111 references in this paper.