Analysis Of Relationships Among Leaf Structural Traits And Economics Spectrum Of The Nine Evergreenbroad Leaved Tree Seedlingsin The Mid-subtropical Zone Of China

Following manual collection of seeds stored in sand under low temperature and then cultivated ingreenhouse,Castanopsis fargesii,Castanopsis sclerophylla and Cyclobalanopsis jenseniana(Fagaceae),Machilus pauhoi,Cinnamomum camphora and Phoebe bournei(Lauraceae),Tsoongiodendron odorum,Michelia chapensls and Michelia maudiae(Magnoliaceae)seedlings from the mid-subtropical zone of China were transplanted to the common garden in the Jiangxi Dagangshan Forest Ecosystem Research Station.Interspecific differences,correlations and economics spectrum in leaf size,leaf thickness,leaf volume,leaf tissue density,specific leaf area,leaf dry matter content,leaf nitrogen concentration,leaf phosphorus concentration,and ratio of nitrogen and phosphorus concentration of two-year old seedlings in the growing season.Results showed that:(1)Among the nine evergreen broad leavedtree seedlings,Castanopsis fargesii has the highest ratio of leaf nitrogen and phosphorus concentration,and the lowest leaf nitrogen concentration and leaf phosphorus concentration.Castanopsis sclerophylla has the highest leaf dry matter content.Cyclobalanopsis jenseniana has the lowest specific leaf area.Machilus pauhoi has the highest specific leaf area and the lowest 1eaf thickness.Cinnamomum camphora has the and the lowest leaf tissue density.Phoebe bournei has the lowest leaf size,1eaf volume and ratio of leaf nitrogen and phosphorus concentration.Tsoongiodendron odorum has the highest 1eaf thickness and leaf nitrogen concentration.Michelia chapensls has the lowest leaf dry matter content.Michelia maudiae has the highest leaf size,1eaf volume,leaf tissue density and leaf phosphorus concentration.(2)Fagaceae has the highest leaf dry matter content,ratio of leaf nitrogen and phosphorus concentration,and it has the lowest specific leaf area,1eaf nitrogen concentration and leaf phosphorus concentration.Lauraceae has the highest specific leaf area,and the lowest leaf size,1eaf thickness,1eaf volume and leaf tissue density.Magnoliaceae has the highest leaf size,1eaf thickness,1eaf volume,leaf tissue density,1eaf nitrogen concentration and leaf phosphorus concentration,and the lowest leaf dry matter content and ratio of leaf nitrogen and phosphorus concentration.(3)Pearson and line regression analyses indicated that leaf size of nine evergreen broad leaved tree seedlings showed highly significant positive correlation with 1eaf thickness,leaf volume,leaf tissue density,1eaf nitrogen concentration and leaf phosphorus concentration(P<0.01),and highly significant negative correlation with 1eaf dry matter content(P< 0.01).Leaf thickness exhibited highly significant positive with 1eaf volume and leaf tissue density(P<0.01),significant positive correlation with leaf phosphorus concentration(P< 0.05),andsignificant negative correlation with 1eaf dry matter content(P<0.05).Leaf volume exhibited highly significant positive correlation with leaf tissue density,1eaf nitrogen concentration and leaf phosphorus concentration(P< 0.01),highly significant negative correlation with 1eaf dry matter content(P< 0.01).Leaf tissue density exhibited highly significant positive correlation with 1eaf nitrogen concentration and leaf phosphorus concentration(P< 0.01),highly significant negative correlation with 1eaf dry matter content(P< 0.01).Specific leaf area exhibited highly significant positive correlation with 1eaf nitrogen concentration and leaf phosphorus concentration(P<0.01),and highly significant negative correlation with 1eaf dry matter content(P< 0.01).Leaf dry matter content exhibited highly significant negative correlation with 1eaf nitrogen concentration and leaf phosphorus concentration(P< 0.01).1eaf nitrogen concentration exhibited highly significant positive correlation with leaf phosphorus concentration(P< 0.01).(4)Leaf size of Fagaceae tree seedlings showed highly significant positive correlation with 1eaf thickness,1eaf volume and 1eaf dry matter content,respectively(P< 0.01),andhighly significant negative correlation with leaf tissue density(P< 0.01).Leaf thickness exhibited highly significant positive correlation with 1eaf volume and 1eaf dry matter content,respectively(P< 0.01),highly significant negative correlation with leaf tissue density(P< 0.01),and significant negative correlation with specific leaf area(P< 0.05).Leaf volume exhibited highly significant positive correlation with 1eaf dry matter content(P< 0.01),and highlysignificant negative correlation with leaf tissue density(P< 0.01).Leaf tissue density exhibitedsignificant negative correlation with 1eaf dry matter content(P< 0.05).Lpecific leaf area exhibited significant negative correlation with 1eaf dry matter content(P< 0.05).(5)Leaf size of Lauraceae tree seedlings showed highly significant positive correlation with 1eaf volume(P< 0.01),highly significant negative correlation with 1eaf dry matter content and leaf phosphorus concentration,respectively(P< 0.01),significant positive correlation with 1eaf nitrogen concentration(P< 0.05),and significant negative correlation with leaf tissue density(P< 0.05).Leaf thickness exhibited significant positive correlation with1 eaf dry matter content(P< 0.05),and significant negative correlation with specific leaf area(P< 0.05).Leaf volume exhibited highly significant positive correlation with 1eaf nitrogen concentration(P< 0.01),highly significant negative correlation with leaf tissue density(P<0.01),and significant negative correlation with leaf phosphorus concentration(P< 0.05).Leaf tissue density exhibited significant positive correlation with leaf phosphorus concentration(P<0.05).Specific leaf area exhibitedhighly significant negative correlation with 1eaf dry matter content and leaf phosphorus concentration,respectively(P< 0.01).Leaf dry matter content exhibited highly significant positive correlation with leaf phosphorus concentration(P< 0.01).(6)Leaf size of Magnoliaceae tree seedlings showed highly significant positive correlation with 1eaf volume and leaf tissue density,respectively(P< 0.01),highly significant negative correlation with specific leaf area and 1eaf nitrogen concentration,respectively(P<0.01).Leaf thickness exhibited highly significant positive correlation with 1eaf dry matter content(P< 0.01).Leaf volume exhibited highly significant positive correlation with leaf tissue density(P< 0.01),highly significant negative correlation with specific leaf area(P<0.01).Leaf tissue density exhibited highly significant negative correlation with specific leaf area and 1eaf nitrogen concentration,respectively(P< 0.01).Specific leaf area exhibited significant positive correlation with 1eaf nitrogen concentration(P< 0.05).Leaf dry matter content exhibited significant positive correlation with leaf phosphorus concentration(P< 0.05).Leaf nitrogen concentration exhibited highly significant positive correlation with leaf phosphorus concentration(P< 0.01).(7)According to the basic research result,although there are strong relationships among leaf structure traits of these nineevergreen broad leaved tree seedlings,the degree of correlation and significance among those leaf structures are still various.(8)According to the further analysis,the location of Magnoliaceaw and Lauraceas in leaf economic spectrum are near to “Quick investment return species”,which are thin leaves with high leaf nitrogen and strong phosphorous function.However,Fagaceae,also named “Slow investment-return species”,will be much closer to the other side,which has thick leaves,low leaf nitrogen and weak phosphorous function.This phenomenon shows that those 9 evergreen broad leaved tree seedlings adapt different strategy for surviving by balancing the relationships between their economic characters.