Abstract: With the planted forest ecosystems of Cercidiphyllum japonicum, Betula utilis, Pinus yunnansinsis, and Picea asperata in subalpine area of west Sichua n as test objects, their total biomass and the C and N contents in soils and tre e organs were determined. The results showed that the allocation of C in tree or gans had less correlation with the age of the organs, while that of N and C/N ra tio had closer relationship with the age. The N content in young organs was high er than that in aged ones, whereas the C/N ratio was higher in aged organs than in young organs, and higher in the leaf litters of needle-leaved forests than i n those of broad-leaved forests. There was an obvious enrichment of C and N in the topsoil of test forests. The accumulated amounts of C and N in the whole pla nted forest ecosystem, including tree, litter, and 0〖KG-*2〗-〖KG-*7〗40 cm soil layer, were 17675〖KG-*2〗-〖KG-*7〗22805 t·hm-2 and 1106〖KG-*2 〗-〖KG-*7〗1654 t·hm-2, respectively, and the nutrients allocation rat io between soil-litter and tree was (19〖KG-*2〗-〖KG-*7〗33)∶〖KG-*2〗1 for C an d (156〖KG-*2〗-〖KG-*7〗415)∶〖KG-*2〗1 for N. Needle-leaved forests functioned as a stronger “C-sink” than broad-leaved forests. The decomposition rate of the l eaf litters in needle-leaved forests was larger than that in broad-leaved fore sts, with the turnover rate being 22〖KG-*2〗-〖KG-*7〗37 years and 39〖KG -*2〗-〖KG-*7〗42 years, respectively. During the decomposition of leaf litter, the C in all of the four forests released at super -speed, with the turnover rate being 19〖KG-*2〗-〖KG-*7〗34 years. As for N, it also released at super-speed in C. japonicum and B. utilis forest s, with the turnover rate being 19〖KG-*2〗-〖KG-*7〗32 years, but released a t low speed in P. yunnansinsis and P. asperata forests, with the turnove r rate being 67〖KG-*2〗-〖KG-*7〗85 years.

Key words: pea, physiological index, exogenous calcium, salt stress, symbiotic rhizobium