Drought-induced shifts in gross primary production pathways in Moso bamboo forests: Insights from improved BIOME-BGC and structural equation modeling
Moso bamboo forest (MBF) is a special forest type widely distributed in subtropical regions with high carbon sequestration potential. However, climate change induced frequent drought events have significantly impacted its carbon fixation capacity, while the response mechanisms still unclear. In this...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-01-01
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| Series: | Ecological Indicators |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X25000627 |
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| Summary: | Moso bamboo forest (MBF) is a special forest type widely distributed in subtropical regions with high carbon sequestration potential. However, climate change induced frequent drought events have significantly impacted its carbon fixation capacity, while the response mechanisms still unclear. In this study, photosynthetic water stress module of BIOME-BGC was improved and optimized by long-term carbon flux observations from the Anji MBF site, then the temporal variations of Gross Primary Production (GPP) were simulated and analyzed from 2000 to 2019. Finally, Random Forest (RF) and Structural Equation Modeling (SEM) were implemented to explore the responses of GPP to drought during different periods of the growing season. The results indicate that: (1) The improved model significantly enhances the accuracy of GPP simulations, with correlation coefficients, root mean square error, and bias values of 0.86 ± 0.05, 1.18 ± 0.07, and 0.93 ± 0.05 g C m−2 day−1, respectively. (2) The GPP shows an overall increasing trend, averaging 1606.09 ± 45.48 g C m−2 yr−1, with reaching its peak in the 2019 growing season at 1682.75 g C m−2 season−1. Drought during different growing seasons (Rapid Growing Season, Main Growing Season, and Final Growing Season) led to decreases in daily GPP of 0.44, 0.52, and 0.28 g C m−2 day−1, respectively. (3) The combined analysis using RF and SEM reveals that temperature and stomatal conductance are the most critical environmental and physiological factors driving GPP variations. However, drought alters the pathways through which environmental factors influence physiological factors, with the main indirect environmental control factor shifting to vapor pressure deficit. |
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| ISSN: | 1470-160X |