Abstract: Taking the mixed leaf litters in broadleaved-Korean pine forests at different succession stages (secondary birch forest, selective cutting forest, and original mixed forest) and the leaf litters of the dominant tree species (Betula costata, Tilia amurensis, and Pinus koraiensis) in these forests in Xiaoxing’an Mountains, China as test objects, this paper studied their remaining rates and nutrient dynamics in October 2006-November 2008 by using decomposition bag method. For all test leaf litters, their remaining rate had an exponential relationship with time. The annual decomposition constant (k) ranged from 0.137 to 0.328, and the time for decomposing 50% (t_50%) and 95% (t_95%) was 2.340-4.989 years and 9.360-21.796 years, respectively. No significant differences were observed in the decomposition rates of the leaf litters among the forests, but the kvalue of the mixed leaf litters was decreased in the order of original mixed forest > selective cutting forest > secondary birch forest, while that of the dominant tree species leaf litters had no obvious pattern. During decomposition, the elements C, P, and K in leaf litters released continuously, and the release pattern of C followed linear function, while that of P and K followed a function of higher degree. Element N presented different levels of accumulation, but had no clear pattern.

Key words: mixed broadleaved-Korean pine forest, succession stage, leaf litter, decomposition rate, nutrient characteristic, sandy land, shrub root, xylem anatomical structure, hydraulic trait.