Tree species richness relates to long-term forest photosynthesis increase
摘要
The widespread increase in vegetation productivity plays an important role in enhancing ecosystem carbon uptake. While it is well established that biodiversity increases ecosystem productivity, its influence on long-term changes in photosynthesis remains unclear. Here we integrate a high-resolution map of tree species richness with satellite-derived photosynthesis proxies during 2001–2020 to show that high richness not only enhances current levels of photosynthesis but also correlates with a greater increase in photosynthesis over time. This pattern is largely driven by an amplified CO2 fertilization effect (CFE) in species-rich forests. The ability of diverse forests to mitigate water and nutrient limitations probably contributes to the CFE enhancement and photosynthesis rise. Projections suggest that biodiversity losses by 2050 could reduce photosynthesis trends by 3–17%, representing a cumulative forest photosynthesis loss of 4.4–35.7 PgC. These findings underscore the critical need to integrate biodiversity conservation into climate mitigation strategies to safeguard the terrestrial carbon sink.