关键词: 坡向, 年轮, 紫果云杉, 岷江冷杉, 快速升温, 青藏高原

Abstract: Pinus tabulaeformis(Carr.) is one of the main forestation tree species in northern China. To accurately estimate the biomass and carbon storage of P. tabulaeformis plantation ecosystem is critical to the study of the carbon sequestration function of regional P. tabulaeformis plantations. By using plot sampling method, this paper measured the biomass, carbon storage, and carbon partitioning of a 38-year-old P. tabulaeformis plantation in Shanxi Province, and estimated the net productivity and annual net carbon sequestration of the plantation. It was found that the biomass of the individual tree was closely correlated with the diameter at breast height and tree height. The mean stand biomass was 145.35 t·hm^-2, of which, tree layer biomass was 123.98 t·hm^-2, accounting for 85.30% of the total. The carbon content in various components of the plantation ecosystem was 0.5032 g C·g^-1 in stem, 0.4887 g C·g^-1 in bark, 0.5414 g C·g^-1 in branch, 0.4774 g C·g^-1 in leaf, 0.4862 g C·g^-1 in root, 0.4468 g C·g^-1 in shrub layer, 0.4417 C·g^-1 in herb layer, 0.4112 g C·g^-1 in litter layer, and 0.0090 g C·g^-1 in soil layer (0-100 cm), and the soil carbon content was decreased gradually with depth. The total carbon storage of the plantation ecosystem was 172.95 t·hm^-2, and the carbon storage of each layer was in the order of soil layer (102.07 t·hm^-2) > tree layer (62.08 t·hm^-2) > litter layer (7.75 t·hm^-2) > shrub layer (0.58 t·hm^-2) > herb layer (0.47 t·hm^-2). The carbon storage in different tree organs was positively correlated with their biomass. Stem had the highest biomass, and its carbon storage was also the greatest, accounting for 58.80% of the tree layer’s. The plantation had an annual net productivity of 10.19 t·hm^-2·a^-1, and its annual net carbon sequestration was 5.03 t C·hm^-2·a^-1.

Key words: slope aspect, tree ring, Picea purpurea, Abies faxoniana, rapid warming, Tibetan Plateau.