[Carbon budget of ecosystem in Changbai Mountain Natural Reserve]

The study used EPPML, a biological geochemistry cycle model that was built, to simulate the carbon budget for ecosystems in Changbai Mountain Natural Reserve. The results indicated that the annual net primary productivity [NPP (carbon)] of the natural reserve was 1.332 x 10(6) t.a-1. The annual NPP of mixed broad-leaved and Korean pine forest and spruce-fir forest were maximal, 0.540 x 10(6) t.a-1 and 0.428 x 10(6) t.a-1 respectively. The area and productivity of the two stands were maximal in Changbai Mountain, therefore, the simulating productivity of the two stands most greatly affect carbon cycle and carbon budget of the natural reserve, and the veracity of the former decides the security of the latter. To sum up, not only did the simulations accord with routines in the relative comparisons between different vegetation belts and climate belts in the whole natural reserve, but also was exact in the absolute comparisons with very disperse data from field survey. Vegetations in the natural reserve had evident carbon sink functions, mainly exhibiting in the increasing of carbon, about 1.058 x 10(6) t.a-1. The annual carbon of mixed broad-leaved and Korean pine forest increased greatest (0.452 x 10(6) t.a-1), secondly spruce-fir forest (0.339 x 10(6) t.a-1). The two stands played crucial roles in the carbon sink for Changbai Mountain, others being Changbai larch forest, broad-leaved forest, meadow, shrub, alpine tundra, subalpine Betula ermanii forest and alpine grass. In 1995, the decomposing carbon of soil organic matter was 0.169 x 10(6) t.a-1 higher than the littering carbon in the natural reserve. There was accumulation of organic matter in the meadow soil and shrub soil. The decomposition and accumulation of soil organic matter was in the nearly balancing condition in the alpine tundra soil and alpine grass soil. The decomposition of organic matter was as one and a half time or double as litterfall in the arbor forest soil.