基于阿尔泰山额尔齐斯河流域2000—2020年土地利用数据，运用InVEST模型，模拟并分析了不同时期该流域碳储量空间分布，并探讨了人类活动对碳储量空间分布的影响。研究表明：（1） 流域内土地利用类型以草地和未利用地为主，2000—2020年土地利用格局发生明显改变，耕地和城乡、工矿、居民用地分别增加2619.35 km²和186.68 km²；草地和水域分别增加4725.13 km²和33.47 km²；林地和未利用地分别减少2328.88 km²和5237.76 km²。（2） 研究期间，流域内碳储量空间分布格局较为相似且呈现带状分布， 高值区分布在高海拔地区，低值区分布在低海拔地区，2000年、2005年、2010年、2015年和2020年流域内碳储量总量分别为641.60 Tg、645.78 Tg、646.83 Tg、650.28 Tg和665.91 Tg，其年增长率为0.95%，呈现上升趋势。（3） 流域内碳储量减少或增加的区域呈现点状分布，2000—2020年碳储量的增加量大于减少量，因此，额尔齐斯河流域的固碳能力呈上升趋势。

Carbon sequestration is among the main functions of terrestrial ecosystem services, and the carbon sequestration capacity of terrestrial ecosystems directly affects global carbon emissions and climate change processes. Human activities directly influence land use and cover change, consequently affecting the carbon sequestration function of ecosystems. The terrestrial ecosystem services in dry and cold regions are more vulnerable and significantly impacted by human activities. Therefore, utilizing land use data from the Irtysh River Basin in the Altai Mountains from 2000 to 2020, the InVEST model was used to estimate and analyze the spatial distribution of carbon stocks in the basin during different periods. Subsequently, the influence of human activities on the spatial distribution of carbon stocks was discussed. The results show the following: (1) The main land use types in the basin are woodland, grassland, and unused land, and the land use pattern changed significantly from 2000 to 2020. Cultivated land, urban and rural land, industrial and mining land, and residential land expanded continuously, increasing by 2619.35 km² and 186.68 km², respectively. Grassland and water areas initially decreased and then expanded, increasing by 4725.13 km² and 33.47 km², respectively. Meanwhile, forest land and unused land decreased continuously by 2328.88 km² and 5237.76 km², respectively. (2) During this period, the spatial distribution pattern of carbon stocks in the basin was similar and showed a zonal distribution. High-value areas were distributed in high-altitude regions where grassland and woodland were clustered, while low-value areas were distributed in low-altitude regions where unused land was clustered. In 2000, 2005, 2010, 2015, 2020 the total carbon storage in the basin was 641.60 Tg, 645.78 Tg, 646.83 Tg, 650.28 Tg, and 665.91 Tg, respectively, with an annual growth rate of 0.95%, showing an upward trend. (3) The areas in the basin where carbon storage decreased or increased showed a spot-like distribution. Furthermore, carbon storage reduction mainly occurred through the conversion of grassland to unused land and cultivated land, with an average annual reduction of 58.81 Tg. The increase in carbon storage primarily resulted from the conversion of unused land into cultivated land and grassland, with an average annual increase of 64.82 Tg. From 2000 to 2020, the net sequestration of carbon storage exceeded the net release, indicating an increasing carbon sequestration capacity in the Irtysh River Basin. Overall, the reclamation of land and grass due to human activities is the main reason for the increase in carbon storage in the basin. However, it is necessary to coordinate the development and utilization of water and soil resources, as this will guarantee not only an increased carbon sink but also the preservation of the carrying capacity of water and soil resources, ultimately achieving sustainable economic development in the Irtysh River Basin. The results of this study will help to promote the carbon cycle of the basin and the carbon sequestration capacity of the ecosystem, as well as provide a scientific basis for the establishment and management of the basin carbon pool.