基于2000年以来塔里木河下游生态输水资料、气象数据、土地利用/覆被变化数据等,结合修正的CASA（Carnegie-Ames-Stanford approach）模型和土壤微生物呼吸模型（Heterotrophic respiration,R_H）估算了2001—2019年植被净生态系统生产力（Net ecosysterm productivity,NEP）,分析了植被碳源/汇空间分布变化,探讨了塔里木河下游生态输水对植被碳源/汇变化的影响。结果表明：（1） 随着2000年以来塔里木河下游生态输水,下游退化的生态系统有一定程度的恢复,植被碳汇区域呈现扩大的趋势。2001—2019年NEP以0.541 g C·m^-2·a^-1的速率呈现上升趋势,其中夏季增加速率最大,为0.406 g C·m^-2·a^-1,增加的区域主要位于大西海子水库北部、英苏、博孜库勒湿地、喀尔达依湿地以及台特玛湖。碳汇面积从2001年的71 km²增加至2019年的355 km²,增加了4倍。（2） 在季节变化上,夏季碳汇面积为109 km²,在四季中占比最大,春秋次之,冬季无明显碳汇面积。（3） 塔里木河下游生态系统碳汇面积变化次序为：草地>林地>耕地>未利用地>水域>建设用地。此外,林地和草地年平均变化率最高,分别为2.69 km²·a^-1和3.57 km²·a^-1。生态输水量与碳汇面积有很好的线性关系,碳汇面积变化存在约1 a的滞后效应。

The net ecosystem productivity (NEP) of vegetation in the lower reaches of Tarim River, Xinjiang, China from the year 2000 was estimated using data of ecological water conveyance, meteorology, land use/cover changes combined with the modified Carnegie-Ames-Stanford approach (CASA) mode and soil microbial respiration models (R_H). The spatial distribution of vegetation carbon sources/sinks was analyzed, and the effect of ecological water conveyance on changes in these sources/sinks in the lower reaches of Tarim River was discussed. Results showed that (1) ecological water conveyance to the lower reaches of Tarim River since 2000 has allowed the degraded ecosystem in this area to recover to a certain extent. In addition, the vegetation carbon sinks in the area showed an increasing trend. Specifically, from 2001 to 2019, NEP showed an increase rate of 0.541 g C·m^-2·a^-1. The maximum increase rate, which was 0.406 g C·m^-2·a^-1, was observed in summer. The areas in which the carbon sinks increased were mainly located in northern Daxihaizi Reservoir, Yingsu, Bozikule Wetland, Kaldayi Wetland, and Taitma Lake. The area of vegetation carbon sinks increased by four times from 71 km² in 2001 to 355 km² in 2019. (2) In terms of seasonal variation, the carbon sink area measured 109 km² in summer. Indeed, this season contributed the largest to the total carbon sink area among the four seasons, followed by spring and autumn. No obvious carbon sink areas were noted in winter. (3) Changes in the total carbon sink area of different ecosystems showed the order grassland>woodland>cultivated land>unused land>water area>construction land. The annual average change rates of the carbon sink areas in woodland and grassland, at 2.69 km²·a^-1 and 3.57 km²·a^-1, respectively, were higher than those of any of the other ecosystems. A good linear relationship between ecological water conveyance and carbon sink area was observed, and changes in carbon sink area indicated a lag effect of approximately 1 year.