Photosynthetic Characteristics And Dynamic Characteristics Of Nutrient In Leaf Of Seedling Of Three Deciduous Broad-Leaved Trees

Gas exchanges indexes, Pn–PPFD curves, chlorophyll content, nutrient condition of the rhizosphere soil and the retranslocation efficiency of nutrient were investigated in three species,they were Liriodendron chinense(Hemsl) Sarg.,Catalpa bungei C.A.Mey and Betula luminifera H.Winkl.The purpose of this experiment was to study the photosynthetic and physiological characteristics of three species,Nitrogen and phosphorus concentrations,N:Pratio,nutrient retranslocation efficiency of mature and senescent leaves of three species and Cunninghamia lanceolata were discussed in this paper.which offered a theoretical basis for they planting model. An expermient was conducted to study the adaptability of one-year-old Betula platyphylla and Betula maxi mowiczianaseed-lingstodry environment and their water adjustment abilitiesby the LI-6400 portable photosynthesis system; mature green leaves and abscising leaves of three species were sampled, samples were dried and determined for organic matter, N, P, K and so on in the laboratory.⑴Pn,Tr and Gs of Liriodendron chinense(Hemsl) Sarg.and Betula luminifera H.Winkl presented double-peak curves,and their Ci appeared W-shaped curves;Pn,Tr and Gs of Catalpa bungei C.A.Mey presented a single-peak curve,and its Ci appeared a V-shaped curve;Liriodendron chinense(Hemsl) Sarg.and Betula luminifera H.Winkl appeared obvious midday depression of photosynthes between11:00 and13:00,and non-stomatal factor caused the decrease of the net photosynthetic rate between 11:00 and 13:00 and between 16:00 and 17:00;but Catalpa bungei C.A.Mey was between 14:00 and 17:00.⑵Pn of the three tested species significantly and positively correlated with PARo,Gs and Tr, positively correlated withTair,negatively correlated with RH-R,significantly and negatively correlated with Ci,Ls of the three tested species significantly and positively correlated with Ci,positively correlated with Tr and VpdL.⑶the order of the Pn wasBetula luminifera H.Winkl>Liriodendron chinense(Hemsl) Sarg.>Catalpa bungei C.A.Mey, the order of the PE was Betula luminifera H.Winkl>Liriodendron chinense(Hemsl) Sarg.>Catalpa bungei C.A.Mey, the order of the CE was Catalpa bungei C.A.Mey>Liriodendron chinense(Hemsl) Sarg.>Betula luminifera H.Winkl, the order of the Gs was Catalpa bungei C.A.Mey > Liriodendron chinense(Hemsl) Sarg.>Betula luminifera H.Winkl, the order of the RH–S was Betula luminifera H.Winkl > Liriodendron chinense(Hemsl) Sarg. > Catalpa bungei C.A.Mey, the order of the Tr wasCatalpa bungei C.A.Mey > Liriodendron chinense(Hemsl) Sarg.>Betula luminifera H.Winkl, the order of the VpdL was Catalpa bungei C.A.Mey > Liriodendron chinense(Hemsl) Sarg. > Betula luminifera H.Winkl, the order of the chl (a+b) was Betula luminifera H.Winkl>Liriodendron chinense(Hemsl) Sarg.>Catalpa bungei C.A.Mey, the order of the chla/b was Catalpa bungei C.A.Mey>Liriodendron chinense(Hemsl) Sarg.>Betula luminifera H.Winkl.⑷the soil horizon was between 1cm and 30cm, the average of totalnitrogen,total phosphorus,rapid available nitrogen,rapid available phosphorus,rapid available potassium and organic matter of Liriodendron chinense(Hemsl) Sarg. were 1.468 g/kg,1.838 g/kg,97.08 mg / kg,2.53 mg / kg,32.95 mg / kg,26.05g / kg.the average of totalnitrogen,total phosphorus,rapid available nitrogen,rapid available phosphorus,rapid available potassium and organic matter of Catalpa bungei C.A.Mey were 0.803 g/kg,0.947 g/kg,69.73 mg/kg,2.15 mg/kg,20.15 mg/kg,19.04g/kg. the average of totalnitrogen,total phosphorus,rapid available nitrogen,rapid available phosphorus,rapid available potassium and organic matter of Betula luminifera H.Winkl were0.689 g/kg,1.615g / kg,75.80mg / kg,2.35 mg / kg,28.11mg / kg,14.10g / kg.⑸the retranslocation efficiency of nitrogen of Liriodendron chinense(Hemsl) Sarg., Catalpa bungei C.A.Mey and Betula luminifera H.Winkl were 0.262 mg·g^-1,0.432 mg·g^-1 and 0.369mg·g - 1, the retranslocation efficiency of phosphorin of Liriodendron chinense(Hemsl) Sarg., Catalpa bungei C.A.Mey and Betula luminifera H.Winkl were 0.136mg·g^-1,0.621 mg·g^-1 and 0.102mg·g^-1, the N:P of leaves of Liriodendron chinense(Hemsl) Sarg. was 12.112, the N:P of leaves of Catalpa bungei C.A.Mey was 18.213, the N:P of leaves of Betula luminifera H.Winkl was10.314.