不同龄级及林分密度天山云杉的碳储量及其分配特征.

To explore variations in carbon storage and distribution patterns across various layers(vegetation layer, litter layer, and soil layer)of different age classes and different densities of Picea schrenkiana var. tianschanica natural forest ecosystem in the northern foot of Tianshan Mountains, a total of 9 kinds of P. schrenkiana var. tianschanica natural forest with low(300～500 tree·hm-2), medium(500～600 tree·hm-2)and high(600～800 tree·hm-2)stand densities under three age classes of the middle-aged forest, near-mature forest and mature forest were selected as the research objects. Carbon storage at different levels in the natural forest ecosystem of P. schrenkiana var. tianschanica was estimated by field investigation and indoor analysis. The results showed that for the aboveground and belowground biomass of tree layer components in P. schrenkiana var. tianschanica, natural forest increased with an increase in stand density in middle-aged and near-mature forests. In contrast, in mature forests, it increased first and then decreased with an increase in stand density. In the herb and litter layers of the natural forest of P. schrenkiana var. tianschanica, the biomass of the litter layer was the main component, accounting for 74. 46%～99. 45%; the herb layer components accounted for only 0. 55%～25. 54%. The vegetation carbon storage of the P. schrenkiana var. tianschanica natural forest increased with an increase in stand density in the middle-aged forest but decreased first and then increased with an increase in stand density in near-mature and mature forests. Soil carbon storage in the P. schrenkiana var. tianschanica natural forest first decreased and then increased with an increase in age class and stand density. The ecosystem carbon storage was the highest in the middle-aged high-density stand(570. 65 t·hm-2)and the lowest in the middle-aged low-density stand(287. 21 t·hm-2). The spatial distribution pattern of carbon storage in the P. schrenkiana var. tianschanica natural forest ecosystem was as follows: carbon storage in the soil layer accounted for the highest proportion, which was 49. 74%～72. 92%, followed by carbon storage in the tree layer(30. 22%～49. 54%), and the proportion of carbon storage in the herb and litter layers was only 0. 32%～2. 28%. The soil layer serves as the primary carbon reservoir in the natural Schrenkiana spruce forest ecosystem, allowing it to effectively store organic carbon as it grows. Middle-to-high-density forests contribute to the accumulation of biomass and carbon. High-density forests in near-mature and mature forests should be moderately thinned to increase the carbon sequestration capacity of the stands. [ABSTRACT FROM AUTHOR]