Effects Of Fertilization,Slope Aspect And Forest Age On Foliage C,N And P Stoichiometry And Essential Oil Components Of Torreya Grandis Cv. Merrillii

Torreya grandis is a rare and endemic tree species in China.It is a plant of the Genus Taxus,and its seeds are edible and medicinal.Torreya grandis cv.Merrillii is an excellent variation and the only cultivar for nut production.In this study,an investigation was conducted to reveal the effects of management regime(fertilization),slope aspect and stand age on the nutrient ecological stoichiometry and essential oil component of foliage in Torreya grandis cv.Merrillii plantations.The results are as follows.(1)The effects of different fertilizations on K and Mg contents were not significant(p>0.05),but significantly affected the N,P content and leaf C,N,P ratios.Among them,foliar age had significant effects on P,Ca contents and C:P,N:P ratios(p<0.05).The interaction between different fertilizations and foliar age had significant effects on N:P ratio and P content(p<0.05).The C,N,P,K,Mg contents are higher in one-year-old foliage than in the others,while C:N,C:P,N:P,Ca are lower in one-year-old foliage than in the others.The interaction between different fertilizations and foliar age had significant effects on N:P ratio and C content(p<0.05).(2)Different slope aspects only had a significant effect on Mg(p<0.05).Leaf age had significant effects on P,C:P,N:P,Ca contents and C:P,N:P ratios(p<0.05).The N,P,and K contents are higher in one-year-old twigs,while C:N,C:P,N:P,and Ca are higher in the twigs over one-year-old.(3)In different aged stands,age had significant effects on N,C:N,N:P,Ca,and Mg(p<0.05),and the contents of C,N,and Mg were 8 years>10 years>12 years.>14 years.N:P ratio and Ca content reached highest at 10 year old.Different foliar ages have no significant effects on C content,and significant effect on the other nutrient.N,P,and K contents are higher in one-year-old twigs,while C:N,C:P,N:P,and Ca higher in the twigs over one-year-old.(4)Under the fertilization,a total of 41 volatile components was identified in the foliage of Torreya grandis cv.Merrillii.The main components were:limonene,a-pinene,?-juniperene,3-decene,?-ylang oleyl alcohol,and big root geranene D.A-caryophyllene and caryophyllene,among which the three chemical constituents of limonene,caryophyllene and ?-caryophyllene have the greatest influence on the foliar traits.RDA results showed that tree height had the most significant effect on foliar essential oil composition(p<0.05).(5)A total of 38 volatile components were identified in the different slope aspects.The main components were limonene,?-pinene,?-juniperene,3-decene,big root geranene D,?-ylang oleyl alcohol.--caryophyllene,juniper-1(6),4-diene.Among them,?-Eryngol,Juniper-1(6),4-diene and ?-ylangitol have the greatest influence on leaf traits.(6)A total of 40 volatile components were identified in the different aged foliage,including limonene,?-pinene,?-juniperene,3-decene,geranyl D,?-ylangitol,A-caryophyllene and ?-eulandene,among which three chemical constituents,3-decene,?-ylangitol,and ?-jussonene,have the greatest influence on leaf traits,and The N:P,K,Ca P,C:N had the most significant effect on leaf essential oil composition(p<0.05).In summary,different fertilization,slope aspects and stand age have significant effects on nutrient contents,essential oil composition of twigs of Torreya grandis cv.Merrillii.The results provides reference for the rational utilization and deep processing of the twigs of Torreya grandis cv.Merrillii other than nut production.