Response Of Functional Traits Of Pinus Tabulaeformis To Elevation And Soil In Songshan,Beijing

In this paper,Pinus,abulaeformis forests in different altitudes of Songshan Nature Reserve in Beijing were taken as the research object,and 32 standard plots of Pinus tabulaeformis forest were set along the elevation gradient.Based on the field survey(recording standard ground information and topographic factors,sampling of Pinus tabulaeformis in sample plots,collection of soil samples in plots)and indoor testing(determination of leaf functional traits,determination of physicochemical properties of soil),the correlations among leaf functional traits(leaf dry matter content,specific leaf area,leaf water content,leaf total phosphorus,total leaf nitrogen,leaf nitrogen-phosphorus ratio)were analyzed.The relationship between soil physical and chemical properties(soil pH,soil total nitrogen,total soil phosphorus,and soil water content)and the effect of soil physical and chemical properties on leaf functional traits.The purpose is to reveal the adaptive strategy of Pinus tabulaeformis on soil conditions and topographic changes in the protected area,and to explore the interaction between the functional traits of the leaves and the environment,so as to provide scientific basis for the protection and management of Pinus tabulaeformis forest.Conclusion as below:(1)There was a significant difference in specific leaf area and leaf phosphorus content(P<0.001)in elevation gradients.With increasing altitude,the specific leaf area and leaf phosphorus content showed a linear downward trend;leaf dry matter content was at an elevation gradient.The differences were significant(P<0.01).The changes along the elevation gradient showed a curve.With the increase of altitude,the dry matter content of the leaves first decreased and then increased.The minimum average value was reached at an altitude of about 960m;leaf water content,leaf Nitrogen content and nitrogen-phosphorus ratio were significantly different in elevation gradients.The gradients along the elevation showed curve changes.As altitude increased,all three gradually increased and reached their maximum average at about 960 m above sea level.The performance is a downward trend.In the vicinity of 960m above sea level,the mean value of LDMC is the smallest,and the average value of LNC and LWC is the largest.Based on this,960m is the most suitable altitude for Pinus tabulaeformis growth in Songshan,Beijing.(2)Correlation analysis showed that there was a significant negative correlation between leaf dry matter content and leaf water content(P<0.01),and a significant negative correlation with leaf area(P<0.05);Leaf nitrogen-phosphorus ratio was significantly negatively correlated with specific leaf area(P<0.05);leaf water content was significantly positively correlated with leaf area(P<0.05);leaf phosphorus content was significantly negatively correlated with leaf nitrogen-phosphorus ratio(P<0.05);leaf nitrogen content and leaf nitrogen and phosphorus ratio was significantly positively correlated(P<0.05).The type of nutrient restriction of Pinus tabulaeformis in Songshan Nature Reserve of Beijing is N-restricted.(3)There was a significant positive correlation between soil total nitrogen content and soil total phosphorus content(P<0.01),and soil total nitrogen content was significantly positively correlated with soil moisture content(P<0.01).The correlation between other soil factors was not significant.(4)The effect of soil factor on leaf area and leaf nitrogen-phosphorus ratio was significant.The specific leaf area was significantly negatively correlated with soil pH(P<0.05),and significantly positively correlated with soil total phosphorus content(P<0.05).At the same time,the ratio of leaf nitrogen-phosphorus was significantly positively correlated with soil pH(P<0.05).And there was a significant negative correlation with soil total phosphorus content(P<0.05).The correlation between other indicators was not significant.The main soil factors that affect the functional traits of Pinus tabulaeformis at different altitudes in Songshan,Beijing,are soil pH and soil total phosphorus.