| 摘要: |
| 基于气象、土壤和遥感数据，利用DAYCENT模型对1971—2020年青藏高原草地生产力进行模拟，并对其进行敏感性分析。结果表明：草地净初级生产力（NPP）对各气候因子的敏感程度从大到小依次为温度、降水量和太阳辐射，其敏感性阈值分别为4 ℃、20%和40%。在空间上，受最高温影响，草地NPP变化量的空间分布为东南高西北低；在降水量影响下，草地NPP变化量的空间分布为由东南向中部逐渐递减；在太阳辐射40%的变动幅度下，草地NPP的变化量整体呈中部低、南部和东北部高的分布趋势。除此之外，气温和降水量共同对草地NPP的影响比单一因子对草地NPP的影响大，表明在暖湿条件下，青藏高原草地NPP对气候变化响应更明显，即草地NPP对气候变化的敏感性会增强。 |
| 关键词: DAYCENT模型 净初级生产力 青藏高原 敏感性分析 |
| DOI：10.7515/JEE222097 |
| CSTR：32259.14.JEE222097 |
| 分类号: |
| 基金项目:国家自然科学基金项目（32260353）；甘肃省重点研发计划（21YF5WA096）；甘肃省自然科学基金项目（1606RJZA077，1308RJZA262） |
| 英文基金项目:National Natural Science Foundation of China (32260353); Key Research and Development Program of Gansu Province (21YF5WA096); Natural Science Foundation of Gansu Province (1606RJZA077, 1308RJZA262) |
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| Sensitivity analysis of grassland net primary productivity to climate change in Qinghai-Xizang Plateau |
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SU Maoxin, ZHANG Meiling*, XU Shibo
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Center for Quantitative Biology, College of Science, Gansu Agricultural University, Lanzhou 730070, China
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| Abstract: |
| Background, aim, and scope Grassland ecosystem is one of the terrestrial ecosystems widely distributed on the earth. The Qinghai-Xizang Plateau, known as the “roof of the world”, accounts for a large proportion of China’s grasslands. Due to the increase of global carbon emissions, global warming has intensified, and the Qinghai-Xizang Plateau has encountered ecological problems such as the decline of grassland productivity. Only by better simulating the adaptation mechanism of the Qinghai-Xizang Plateau ecosystem to climate change, in order to accurately predict the impact of future climate change on the ecosystem of the Qinghai-Xizang Plateau. Materials and methods The method used in this paper is the DATCENT model. The meteorological data of this study comes from the website of the China Meteorological Data Service Center (http://data.cma.cn/). The meteorological data is from the soil type data provided by the World Soil Database V1.2, and the remote sensing data is from the earth observation system of NASA (https://www.nasa.gov/) and University of Maryland website GLCF. Results The NPP of grassland changes by 17.34, 8.24, 0.29 and 0.26 g·m−2·a−1 (calculated in C) on average for each unit of change in maximum temperature, minimum temperature, precipitation and solar radiation. The sensitivity thresholds of maximum (low) temperature, precipitation and solar radiation are 4 ℃, 20% and 40% respectively. Spatially, grassland NPP shows different trends under the influence of various climatic factors. In addition, the influence of both temperature and precipitation on grassland NPP is greater than that of a single factor. Discussion By analyzing the single-factor relationship between grassland NPP and temperature, precipitation and solar radiation, it was found that the sensitivity of grassland NPP to these climatic factors varies significantly. Among them, grassland NPP shows a relatively high sensitivity to different variations in the maximum temperature, while its sensitivity to the minimum temperature is slightly lower. In addition, under different changes in precipitation and solar radiation, grassland NPP shows a relatively low sensitivity to them. Subsequently, through the research and analysis of the relationship between grassland NPP and the two factors of temperature and precipitation, it was found that the combined influence of these two factors on grassland NPP is greater than that of a single factor, with temperature being the dominant factor. Conclusions According to the above analysis, the sensitivity of grassland NPP to various climatic factors is the highest temperature, the lowest temperature, precipitation and solar radiation, with sensitivity thresholds of 4 ℃, 20% and 40% respectively. Through the comprehensive analysis of these four sensitive factors, it is found that the grassland NPP is positively correlated with the highest temperature, lowest temperature and precipitation, and negatively correlated with solar radiation. Moreover, changes in temperature and precipitation together had a greater impact on grassland NPP, and temperature was the dominant factor. Recommendations and perspectives The analysis shows that if the climate continues to develop towards warm and humid in the future, the sensitivity of grassland NPP on the Qinghai-Xizang Plateau will continue to increase, which provides a direction for the adaptive management of grassland on the Qinghai-Xizang Plateau in the future. However, only three climate factors have been studied in this paper, and other climate factors may also have an impact on grassland NPP, so corresponding research can be continued in this direction. |
| Key words: DAYCENT model net primary productivity Qinghai-Xizang Plateau sensitivity analysis |
