Research On The Carbon And Plant Nutrients Storages Of Young Dalbergia Odorifera Plantation

The 6 years old Dalbergia Odorifera plantation in the Nanning county of Guangxi province was selected, and the biomass and their productivity; carbon content, storage and distribution pattern; N、P、K、 Ca、Mg nutrient content, storage and distribution; and Cu、Zn、Fe、Mn、 B microelements content, storage and distribution pattern of the Dalbergia Odorifera plantation were analised,in order to learn more about the tree species characteristics of Dalbergia Odorifera, providing the reference for the development of the Dalbergia Odorifera precious species in the southern subtropical region. The results showed that:(1) The vegetation biomass of albergia Odorifera plantation ecosystem was 46.71t/hm2, and the tree layer, understory shrub grass layer and litter layer were 39.04、1.72 and 5.95 t/hm2 respectively. The biomass of various organs showed that stem>lateral branch>great brach>root tip>leaf>root>bark>the fruit. the net productivity of albergia Odorifera plantation was 6.53 t/(hm2.a), with a low productivity.(2) The carbon density in each organs of albergia Odorifera ranged between 446.17-478.3 g/kg, as the orders of fruit>leaf>root tip>lateral branch>stem>great brach>root>bark. Carbon density of undervegetation layer and litterfall layer were 346.9 g/kg and 394.6 g/kg, and the carbon content in 0～20,20～40,40～60,60～100 cm of soil layer were 4.25, 2.74,1.77,1.24 g/kg, respectively, with a low carbon content.(3) The total carbon storage of albergia Odorifera plantation ecosystem was 51.11 t/hm2, and the carbon storage of tree layer was 17.81 t/hm2, shrub and herb layer and litterfall layer were 0.60,2.35 t/hm2, soil layer was 30.35 t/hm, respectively. Soil layer was the main carbon reserve in this ecosystem. The net amount of carbon sequestration was 2.971/(hm2.a), the carbon sequestration ability was relatively low.(4) Those 5 kinds of nutrient elements average content of albergia Odorifera were expressed as N>K>Ca>Mg>P, the ability of enrichment of nutrients was relatively hight. The distribution pattern of nutrients content in various organs were not the same, the nutrients content in leaf, the fruits,branches,bark and roots showed that N>K>Ca>Mg>P, while stem and root tip were N>K>P>Ca>Mg.The total storage of those 5 kinds of nutrient elements in albergia Odorifera plantation was 1138.09 kg/hm2, with the order of showed that P>Mg>Ca>K>N. And the annual net accumulation of these 5 kinds of nutrient elements was 189.7 kg.hm-2.a-1.(5) the average contents of 5 kinds of microelements in albergia Odorifera plantation were expressed as Fe>Mn>Zn>B>Cu. And the total storage was 8894.86 g/hm2, with the orders of Fe>Mn>Zn>B>Cu, the results showed that albergia Odorifera need relatively more Fe element than the other microelements during the growth process. Annual net accumulation of these microelements was 1482.48 g.hm-2.a-1.