氮、磷添加对不同种植密度樟树幼苗碳储量及其分配的影响  

Effects of nitrogen and phosphorus additions on carbon storage and allocation of Cinnamomum camphora seedlings under different planting densities

作　　者：余明 蔡金桓 薛立 YU Ming;CAI Jinhuan;XUE Li(College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学林学与风景园林学院

出　　处：《华南农业大学学报》2020年第1期116-123,共8页Journal of South China Agricultural University

基　　金：中央财政林业科技推广示范项目(2015-GDTK-07)

摘　　要：【目的】对氮(N)、磷(P)添加条件下4种种植密度的樟树Cinnamomum camphora幼苗各器官碳(C)含量、储量和分配比例进行研究,以期为氮沉降和磷添加背景下森林碳储量分配格局的变化提供参考。【方法】以1年生樟树幼苗为试验材料,选择氯化铵(NH4Cl)作为氮肥模拟氮沉降,以二水合磷酸二氢钠(NaH2PO4·2H2O)作为磷添加,设置4个水平:不加N和P(对照,CK),加N,加P,加N和P(N+P)。N、P及N+P每年的添加量分别为NH4Cl 40 g·m^−2、NaH2PO4·2H2O 20 g·m^−2和NH4Cl 40 g·m^−2+NaH2PO4·2H2O 20 g·m^−2;种植密度设置4个水平,即10、20、40和80株·m^−2。【结果】各氮、磷添加和密度处理下幼苗的根、茎和枝的C含量基本上差异不显著,而添加N和N+P能够促使樟树幼苗叶的C含量上升。随着种植密度的增大,樟树幼苗叶片C含量表现出下降的趋势;N、P添加处理基本上能够促进幼苗单株C储量和单位面积C储量的增加;随着种植密度的增大,单株幼苗C储量呈现下降的趋势。【结论】樟树幼苗叶的单株C储量和单位面积C储量分配比例随着种植密度的增大逐渐减小。高密度种植有利于茎的分配比例增加。N+P添加处理对幼苗C储量的促进效果大于单一N或P添加处理。【Objective】To study carbon(C)content,storage and allocation in seedling organs of Cinnamomum camphora cultivated in four different densities under nitrogen(N)and phosphorus(P)additions,and provide information for forest C storage and allocation under the background of N deposition and P addition.【Method】The 1-year-old C.camphora seedlings were used as test materials.NH4Cl and NaH2PO4·2H2O were selected to simulate atmospheric N deposition and P addition,respectively.N and P additions were performed with four different levels(control,N,P,and N+P).The N and P addition amounts per year in N,P,and N+P treatments were 40 g·m^−2 NH4Cl,20 g·m^−2 NaH2PO4·2H2O and 40 g·m^−2 NH4Cl+20 g·m^−2 NaH2PO4·2H2O,respectively.Seedlings were planted in four different densities(10,20,40 and 80 seedlings·m^−2).【Result】C contents in roots,stems and branches of seedlings in all treatments had no significant difference.N and N+P treatments increased C content of leaves.With the increase of planting density,C content of leaves tended to decrease.The N and P additions increased C storage per seedling and C storage in unit area.C storage per seedling decreased with the increase of planting density.【Conclusion】C storage of leaves per seedling and C storage in unit area decreases with the increase of planting density.C storage percentage of stems increases in high cultivation density treatment.The effect of N+P treatment on C storage per seedling and C storage in unit area is greater than that of single N or P addition.

关 键 词：氮、磷添加 林分密度 碳储量 樟树 

分 类 号：S718.52[农业科学—林学]