The Distribution Pattern Of Carbon And Nitrogen In Eucalyptus Plantations Under1,3,5Ages

To develop and utilize Eucalyptus resources, the contents, storage and distribution pattern of carbon and nitrogen in Eucalyptus plantations and its understory vegetation were evaluated in Li Xin station, Qi Po Forestry Farm of Guang Xi province, including plantations of1,3and5years. The results showed:(1)The variation of carbon content in different organs of arbor layer in Eucalyptus forest under1,3,5different ages was small. The carbon contents of organs were between47.9%-53.1%,46.9%-54.9%,48.5%-54.7%respectively, highest in the leaf and lowest in the bark. The significant difference between different organs and different ages was found through the multiple comparison analysis.(2) The nitrogen contents of arbor layer in Eucalyptus forest under1,3,5different ages were between0.42%-2.41%,0.36%-2.25%,0.21%-2.14%respectively. Besides, the nitrogen contents of leaf were significantly higher than those of other organs, all lowest in the truck. Meanwhile, the difference between different organs and different ages were significant.(3).The carbon storage of vegetation layer are increased with the ages of Eucalyptus plantation, which were6.55t·hm-2,49.38t·hm-2,110.34t·hm-2. The nitrogen storages of Eucalyptus forest vegetations were three years old (300.69kg·hm-2)> five years old (206.60kg·hm-2)> one year old (132.68three years old, respectively.(4)With the ages increasing, the nitrogen storage in bush and herbal layer decreased, and the nitrogen storage in litterfall layer increased(5)Besides,the carbon and nitrogen storages in soil layer were higher than those in vegetation layer. In arbor layer, the nitrogen storages were highest in the leaf of1,3years old plantation, while highest in the trunk of5years old plantation. Meanwhile, the carbon storages of three different age forest were major in the trunk.(6)The average carbon contents of prominent shrubs leaf in three different age Eucalyptus forest w-2), respectively.(7) The average carbon contents of prominent herbs in three different age Eucalyptus forest were46.74%(39.09%-49.28%), and the nitrogen contents were between0.90%-1.93%, the C/N rate were between22.36-54.75.