我国南亚热带几种人工林生态系统碳氮储量

Abstract

Carbon and nitrogen storage in different plantation ecosystems of Erythrophleum fordii,Castanopsis hystrix and Pinus massoniana in subtropical south China were studied.The results showed that the allocation of C in the organs of the different tree species had no significant correlation with their age,while that of N had closer relationship with the age.The N concentration in young organs was higher than that in aged ones and the C/N ratio was higher in aged organs than that in young ones.The N concentration was higher in all components of the nitrogen-fixing species(E.fordii plantation) than that in other species(C.hystrix and P.massoniana plantations).There was an obvious enrichment of C and N in the topsoil of the plantation ecosystems.The total ecosystem carbon storage of E.fordii,C.hystrix and P.massoniana plantations was 236.22 t/hm2,267.84 t/hm2 and 200.57 t/hm2 and nitrogen storage was 17.91 t/hm2,12.38 t/hm2 and 10.59 t/hm2,respectively.Carbon storage of tree layer occupied 42.57%,36.31% and 40.28% while 0—100 cm soil occupied 55.77%,62.52% and 57.83%,respectively.Nitrogen storage of soil occupied 92.00%,93.72% and 95.53%.Our study indicated that most ecosystem carbon and nitrogen storage of the plantations stored in soil.Carbon sequestration ability of C.hystrix plantation is higher compared to other two plantations.