Functional Traits And Influencing Factors Of Larix Principis-rupprechtii Plantations In Different Stand Densities

Plant functional traits have been a hot topic in ecological research,which reflects the response of plants to environmental changes.Studying the relationship between plant functional traits and response to environmental factors is helpful to understand plant growth strategy.Based on the low and high densities of Larix principis-rupprechtii plantations,Eight leaf functional traits index and seven twig functional traits index are selected to analyze the characteristics of leaf and twig functional traits of Larix principis-rupprechtii plantations,the relationship between functional traits and environmental factors under different stand densities in Qiliyu,Shanxi Province,The purpose of this study is to explore the relationship between functional traits and environmental factors of Larix principis-rupprechtii plantations.The main conclusions are as follows:(1)Leaf water content is positively correlated with leaf thickness,leaf nitrogen and phosphorus content,and negatively correlated with leaf tissue density and leaf carbon content.Leaf dry matter content is positively correlated with leaf tissue density and leaf carbon content,and negatively correlated with leaf thickness,leaf nitrogen and phosphorus content.There is a positive correlation between specific leaf area and leaf thickness,leaf nitrogen,phosphorus content,and negatively correlate with leaf tissue density.There is a negative correlation between leaf thickness and leaf tissue density.There is a positive correlation between leaf nitrogen and phosphorus content.There is a positive correlation between twig length and twig diameter,leaf phosphorus content,and negatively correlated with twig nitrogen content.Twig diameter is positively correlated with twig carbon content,leaf carbon and nitrogen content.Leafing intensity based on the twig volume is negatively related with twig nitrogen content,but positively correlated with leaf phosphorus content.Twig dry matter content is positively correlated with leaf nitrogen content.Twig carbon content is negatively correlated with twig phosphorus content,and positively correlated with leaf carbon content and leaf nitrogen content.Twig nitrogen content is negatively correlated with leaf phosphorus content.Twig phosphorus content is positively correlated with specific leaf area and leaf phosphorus content,and negatively correlated with leaf carbon content and nitrogen content.(2)The leaf water content,leaf dry matter content,leaf thickness,leaf carbon and nitrogen content in the low and high densities are all arbor layer>shrub layer>herbs layer,and the low densities are less than the high densities.In contrast to specific leaf area,which of the low densities is shrub layer>arbor layer>herbs layer,which of the high densities is arbor layer>shrub layer>herbs layer,which of the low densities arbor layer is less than the high densities,shrub layer and herbs layer are larger than the high densities.The leaf tissue density of the low and high densities is arbor layer>shrub layer>herbs layer.The leaf tissue density of arbor layer in the low densities is greater than which of the high densities,and the shrub layer and herbs layer are less than the high densities.Leaf phosphorus content in the low densities is the arbor layer>shrub layer>herbs layer,and which of the high densities is arbor layer>herbs layer>shrub layer,which of the low densities is less than the high densities.In terms of twig functional traits,which are the arbor layer>shrub layer>herbs layer in the low and high densities,and which of the low densities are less than the high densities.(3)Soil water content,soil total carbon and total nitrogen content in the low and high densities decreases with the deepening of soil layer.The soil water content,soil total carbon and total nitrogen contents of each soil layer in the low densities are greater than which of the high densities.With the gradual deepening of the soil layer,soil total phosphorus content in the low densities decreases firstly and then increase,and soil total phosphorus content in the high densities shows an upward trend,and soil total phosphorus content in the high densities is greater than which of the low densities.(4)Leaf functional traits of arbor layer in the low and high densities are mainly affected by altitude and soil total phosphorus,Altitude is the main factor that affects the twig functional traits of arbor layer.Among them,the twig functional traits in the low densities are also affected by soil total carbon content.For shrub layer,the leaf functional traits of the low densities are mainly affected by soil total phosphorus content,while that in the high densities are affected by soil total nitrogen and soil water content.Altitudes and soil total carbon content are the main factors that affect the twig functional traits of the shrub layer in the low densities,and the main factor which affects the functional traits of the shrub layer in the high densities is total soil carbon content.Soil total phosphorus is the main environmental factor that affects the functional traits of the herbs layer in the low densities.The main environmental factor which affects functional traits of herbs layer in the high densities is soil total carbon.