Attribution of vegetation fluorescence changes in China based on a decision tree stratification strategy

Vegetation photosynthesis plays a key role in maintaining carbon balance in terrestrial ecosystems. Solar-Induced chlorophyll Fluorescence (SIF) was utilized as a proxy for vegetation photosynthesis in this study, and the Theil-Sen and Mann-Kendall methods were used to examine trends of vegetation change in China. The impacts of climate conditions on vegetation photosynthesis were examined with the correlation analysis and recursive feature elimination (RFE) method. To distinguish the contributions of climate change and human activities on vegetation photosynthesis, land use data and SIF change trends were employed as inputs to a decision tree model. The results revealed that 81.5% of the areas in China exhibited an improving trend of vegetation photosynthesis. Vegetation degradation areas were mainly located in Northern arid and semi-arid region (NASR), Qinghai Tibet Plateau (QTP) and Huang-Huai-Hai Plain (HHHP). Precipitation dominated the effect of vegetation photosynthesis in these regions. The increase of vegetation photosynthesis in the southern regions was positively impacted by solar radiation. The growth of agricultural technology obviously benefited the improvement of vegetation photosynthesis in the Middle-lower Yangtze Plain (MLYP) and Northeast China Plain (NCP). Furthermore, the establishment of ecological conservation programs has helped to restore vegetation in arid and semi-arid areas. The detrimental effects of human activities included overgrazing disturbance and coal mining activities, which resulted in vegetation deterioration in areas of QTP and HHHP. The methodologies and findings of this study can help to comprehend changes in vegetation dynamics and give a theoretical foundation for evaluating regional ecological conservation initiatives.(c) 2023 COSPAR. Published by Elsevier B.V. All rights reserved.

Automated summary

This study used Solar-Induced chlorophyll Fluorescence (SIF) as a proxy for vegetation photosynthesis and examined the impacts of climate conditions on vegetation photosynthesis. The results showed that 81.5% of China's areas exhibited an improving trend of vegetation photosynthesis. Agricultural technology contributed to the increase in vegetation photosynthesis in the southern regions, while overgrazing disturbance and coal mining activities led to vegetation deterioration in the Qinghai Tibet Plateau and Huang-Huai-Hai Plain.