Growth Differences Of Male And Female Trees Of Fraxinus Mandshurica On The Different Stand Densities

Stand density has an important effect on the growth and development of individual trees.There are also differences in individual morphology and developmental processes between different sexes of dioecious plants.Do male and female growth and development respond equally to changes on the stand density?What are the morphological differences between male and female individuals on the same density in a plantation?Are the differences in morphogenetic development,morphology,and growth between male and female on the different stand densities?No reports yet.Fraxinus mandshurica is a dioecious tree,and it is one of the important afforestation and precious timber species in Northeast China.In this study,20 species of Fraxinus mandshurica were planted on the 4 types of stand density.The male and female in the plantation were taken as the research object,and the differences between male and female development process and individual growth of Fraxinus mandshurica On the different densities were analyzed.The results are as follows:1.On the low density(T1 and T2),the proportion of males entering reproductive growth was significantly higher than that of high density(T3 and T4)stands.On the T1 density,the proportion of males entering reproductive growth was 2.94 times and 2.27 times that of T3 and T4,respectively,and on the T2 density,the ratio of males entering reproductive growth was 3.02 times and 2.33 times of T3 and T4 respectively.As the forest density increased,the proportion of females entering reproductive growth was not significantly different.On the T1 and T2 densities,the proportion of males entering reproductive growth was significantly higher than that of females.On the T1 and T2 densities,males entering reproductive growth were 1.91 times and 2.33 times of females,respectively.On the 4 sampling scales of 4 densities(6mx6m,6m×12m,12m×12m,12mx24m)Fraxinus mandshurica male and female individuals are randomly distributed,and reproductive growth of ash males and females on the 4 densities are dominant wood.2.The crown morphology of male and female of Fraxinus mandshurica on the different densities is different.with increasing density,the branch angle,branch diameter,number of branches,and number of existing dead branches of male and female Fraxinus mandshurica are all increased.It showed a downward trend,and the females were larger than the males under the four densities;as the density increased,the vertical and horizontal axis lengths of the leaves of male and female Fraxinus mandshurica,single leaf area,fresh mass,and biomass decreased.And the females were larger than the males on the T1,T2,and T3 densities,and smaller than the males on the T4 densities;as the density increased,the leaf shape index of the males of Fraxinus mandshurica increased,and the females first decreased and then increased,and the females increased on the T1,T4 density is higher than males,T2 and T3 densities are lower than males;the specific leaf weight of male and females of Fraxinus mandshurica decreases first and then increases with increasing density,and females are higher than males on the T1 and T2.On the density of T3 and T4,it was lower than that of the male plant.The water content of male and female leaves of Fraxinus mandshurica rose first and then decreased with the increase of the density.The females were higher than the maleson theall four densities.3.On the T1 and T2,the radial growth of female Fraxinus mandshurica from 2008 to 2018 is greater than that of males.On the the T3 density,the annual radial growth of female Fraxinus mandshurica from 2008 to 2012 is higher than males.The annual radial growth of femaleFraxinus mandshurica in 2018 is lower than that of males.The annual radial growth of female Fraxinus mandshurica on the T4 density from 2008 to 2014 is higher than that of males.From 2015 to 2018 The annual radial growth of the plant is lower than that of the male plant;on the T1 and T2 densities,the radial growth of the male and females of Fraxinus mandshurica is positively correlated with the average temperature in April and August and the average precipitation in August,The monthly average temperature was significantly negatively correlated.On the T3 and T4 densities,the radial growth of male and female Fraxinus mandshurica was significantly negatively correlated with the average temperature and precipitation in August of the previous year.It can be seen that different densities have certain effects on the gender development process,branch and leaf traits,and radial growth of male and female Fraxinus mandshurica.Therefore,when cultivating Fraxinus mandshurica plantation forest stand,we should choose an appropriate density according to the purpose of cultivation.While promoting the growth of dried Fraxinus mandshurica,we also take into account the gender development of the plant to provide guarantee for sustainable management of Fraxinus mandshurica.