| 摘要: |
| 探究西南地区植被生态系统（农田、林地和草地）GPP时空变化以及气候因子对其变化的影响，对全球气候变化背景下植被资源分类管理具有重要的意义。该研究基于2000—2022年植被GPP、气温和降水数据，以及2020年土地利用类型数据，基于Theil-Sen Median趋势分析和Mann-Kendall显著性检验，解析西南地区植被生态系统GPP时间变化特征和空间变迁格局；通过通径分析，揭示气温和降水对植被GPP的直接、间接和综合影响及其主导影响因子。结果表明：（1）2000—2022年西南地区各植被生态系统GPP呈显著上升趋势（P<0.05），其中，农田生态系统GPP上升速率最高，草地生态系统GPP上升速率最低。（2）区域尺度上，西南地区气温对植被GPP的直接、间接和综合影响均为正向作用，而降水对植被GPP的影响均为负向作用。气温对草地生态系统GPP变化的直接影响最大，降水对农田生态系统GPP变化的直接影响最大。（3）像元尺度上，气温对西南地区和各生态系统GPP变化的影响强于降水。气温直接影响主导54.89%植被GPP变化。综上可知，西南地区植被生态系统植被GPP呈正向变化的面积占比较大，气温的直接影响是主导各植被生态系统GPP变化的主要方式。该研究结果能够为在全球气候变化情境下，制定具有区域针对性的生态恢复与管理政策提供有价值的参考依据。 |
| 关键词: 西南地区，植被生态系统，GPP，气候因子，通径分析 |
| DOI：10.11931/guihaia.gxzw202407043 |
| 分类号: |
| 基金项目:广西重点研发计划项目“广西自然资源卫星遥感智能监测关键技术与应用示范”(编号：桂科AB22080080)； 高分辨率对地观测系统重大专项政府综合治理应用于规模化产业化示范项目“高分专项广西南方生态屏障遥感监测体系建设与应用”(编号：84-Y50G25-9001-22/23)。第一作者：谢宗音(1986—),学士,高级工程师,主要从事摄影测量与遥感方面的研究,Email: 247807325@qq.com。 *通信作者：黎珍惜,硕士,高级工程师,主要从事地理信息与遥感应用研究,Email::ygysy_2024@163.com。 , 黎珍惜1* |
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| Temporal and spatial variations of gross primary productivity (GPP) in vegetation ecosystems and its dominant climatic factors identification in Southwest China |
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XIE Zongying, LI Zhenxi*
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Guangxi Zhuang Autonomous Region Institute of Natural Resources Remote Sensing, Nanning 530000, China
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| Abstract: |
| Exploring the spatiotemporal variations of Gross Primary Productivity (GPP) across vegetation ecosystems (cropland, forest, and grassland) in Southwest China, as well as the direct, indirect, and comprehensive impacts of climatic factors on these variations, holds significant importance for managing regional vegetation resources amidst climate change. Based on GPP, temperature, and precipitation data spanning from 2000 to 2022, coupled with land use type data from 2020, this study adopts methods such as Theil-Sen Median trend analysis, Mann-Kendall significance test, and path analysis to investigate the spatiotemporal patterns of GPP within Southwest China''s vegetation ecosystems. It further dissects the direct, indirect, and overall effects of temperature and precipitation on vegetation GPP, revealing the dominant climatic factors and their modes of influence on GPP changes in the region. The findings are as follows: (1) From 2000 to 2022, a significant upward trend (P<0.05) was observed in GPP across all vegetation ecosystems in Southwest China, with the cropland ecosystem experiencing the highest increase rate, and the grassland ecosystem, the lowest. (2) At the regional scale, temperature had a positive direct, indirect, and overall effect on vegetation GPP, whereas precipitation exerted a negative influence. Temperature had the most significant direct impact on grassland ecosystem GPP, while precipitation''s direct impact was greatest on cropland ecosystem GPP. (3) At the pixel scale, temperature''s influence on GPP changes in Southwest China and its individual ecosystems was stronger than that of precipitation. Temperature directly dominated 54.89% of the changes in vegetation GPP. In summary, a considerable proportion of vegetation ecosystems in Southwest China showed positive changes in GPP, with temperature''s direct effect being the primary driver of GPP variations across these ecosystems. These findings provide valuable insights for formulating regionally adaptive ecological restoration and management policies amidst global climate change. |
| Key words: Southwest China, vegetation ecosystem, gross primary productivity (GPP), climatic factors, path analysis |
