| 新疆天山北坡荒漠草原碳通量特征及其对环境因子的响应 |
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| 引用本文： | 郭文章,井长青,邓小进,陈宸,赵苇康,侯志雄,王公鑫.新疆天山北坡荒漠草原碳通量特征及其对环境因子的响应[J].草业学报,2022,31(5):1-12. |
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| 作者姓名： | 郭文章 井长青 邓小进 陈宸 赵苇康 侯志雄 王公鑫 |
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| 作者单位： | 新疆农业大学草业与环境科学学院，新疆草地资源与生态重点实验室，新疆 乌鲁木齐 830052 |
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| 基金项目： | 新疆维吾尔自治区重点实验室开放课题;国家自然科学基金 |
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| 摘 要： | 荒漠草原是天山北坡广泛分布的草地类型，对天山北坡草地生态系统碳收支具有重要的调节作用。为阐明天山北坡荒漠草原生态系统碳通量变化特征及环境因子对碳通量的影响，以新疆天山北坡荒漠草原为研究对象，利用微气象观测系统和LI-840 CO2/H2O红外分析仪获得连续观测数据，定量分析了荒漠草原碳通量的变化特征及其影响因子。结果表明：天山北坡荒漠草原植被净生态系统碳交换速率在日尺度上呈倒“U”型曲线；在季节尺度上，6、7、8月表现为碳汇，9、10月表现为碳源；6-10月荒漠草原总固碳量为15.50 g C·m-2，8月固碳量最高为23.03 g C·m-2；生态系统呼吸速率日变化呈“单峰”曲线；在季节尺度上，碳排放呈现先增加后降低趋势，7月碳排放量最高128.42 g C·m-2，10月荒漠草原生态系统碳通量日变化不明显。光合有效辐射是影响日间净生态系统碳交换速率的主导因子，二者符合直角双曲线模型，日间净生态系统碳交换速率随光合有效辐射增大而减小；生态系统呼吸速率与5 cm土壤温度关系符合Van，t Hoff模型，温度敏感性系数Q10为1.69；最适土壤含水量是0.16 m3·m-3，土壤含水量过高或过低均会对荒漠草原生态系统呼吸速率产生抑制作用。
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| 关 键 词： | 碳通量 生态系统呼吸速率 荒漠草原 环境因子 |
| 收稿时间： | 2021-04-13 |
| 修稿时间： | 2021-05-26 |
Variations in carbon flux and factors influencing it on the northern slopes of the Tianshan Mountains |
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| GUO Wen-zhang,JING Chang-qing,DENG Xiao-jin,CHEN Chen,ZHAO Wei-kang,HOU Zhi-xiong,WANG Gong-xin.Variations in carbon flux and factors influencing it on the northern slopes of the Tianshan Mountains[J].Acta Prataculturae Sinica,2022,31(5):1-12. |
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| Authors: | GUO Wen-zhang JING Chang-qing DENG Xiao-jin CHEN Chen ZHAO Wei-kang HOU Zhi-xiong WANG Gong-xin |
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| Institution: | College of Grassland and Environment Sciences，Xinjiang Agricultural University，Key Laboratory of Grassland Resources and Ecology of Xinjiang，Urumqi 830052，China |
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| Abstract: | The desert steppe is a widely distributed grassland type on the northern slopes of the Tianshan Mountains， and it plays an important role in regulating the carbon balance of the grassland ecosystem in this area. The aim of this study was to elucidate the characteristics of carbon flux in desert steppe ecosystems on the northern slopes of the Tianshan Mountains and to determine the main environmental factors that influence carbon flux. A micro-meteorological observation system and a LI-840 CO2/H2O infrared analyzer were used to obtain continuous observation data. The data were quantitatively analyzed to detect variations in carbon flux in the desert steppe and the factors that influence it. During the growing season， the net ecosystem carbon exchange of desert steppe vegetation on the northern slopes of the Tianshan Mountains showed an inverted “U” curve on a daily scale. On a seasonal scale， the vegetation was a carbon sink in June， July， and August； and a carbon source in September and October. The total carbon assimilation in the desert steppe from June to October was 15.50 g C·m-2， and the highest carbon assimilation was 23.03 g C·m-2 in August. The trend in the ecosystem respiration rate showed a “single-peak” curve on a daily scale. On a seasonal scale， carbon emissions showed a trend of increasing and then decreasing， with the highest carbon emissions of 128.42 g C·m-2 in July. The daily variation in carbon flux in the desert steppe ecosystem was not significant in October. Photosynthetically active radiation was the main factor influencing the daily net ecosystem carbon exchange， and the relationship between these two factors fitted a rectangular hyperbola model. The daily net ecosystem carbon exchange decreased with increasing photosynthetically active radiation. The relationship between ecosystem respiration and the 5 cm soil temperature fitted the Van’t Hoff model， with a temperature sensitivity coefficient Q10 of 1.69 and an optimum soil water content of 0.16 m3·m-3. Excessively high or low soil water contents inhibited ecosystem respiration in this area. |
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| Keywords: | carbon flux ecosystem respiration desert steppe environmental factor |
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