Triose phosphate utilization (TPU) limitation is one of the three biochemical limitations of photosynthetic CO₂ assimilation rate in C₃ plants. Under TPU limitation, abrupt and large transitions in light intensity cause damped oscillations in photosynthesis. When plants are salt-stressed, photosynthesis is often down-regulated particularly under dynamic light intensity, but how salt stress affects TPU-related dynamic photosynthesis is still unknown. To elucidate this, tomato (Solanum lycopersicum) was grown with and without sodium chloride (NaCl, 100 mM) stress for 13 d. Under high CO₂ partial pressure, rapid increases in light intensity caused profound photosynthetic oscillations. Salt stress reduced photosynthetic oscillations in leaves initially under both low- and high-light conditions and reduced the duration of oscillations by about 2 min. Besides, salt stress increased the threshold for CO₂ partial pressure at which oscillations occurred. Salt stress increased TPU capacity without affecting Rubisco carboxylation and electron transport capacity, indicating the up-regulation of end-product synthesis capacity in photosynthesis. Thus salt stress may reduce photosynthetic oscillations by decreasing leaf internal CO₂ partial pressure and/or increasing TPU capacity. Our results provide new insights into how salt stress modulates dynamic photosynthesis as controlled by CO₂ availability and end-product synthesis.

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Aims: Common welfare is one of the three foundational concepts in the establishment of Chinese national parks. Existing research predominantly focused on theoretical and qualitative analyses, with few empirical explorations and quantitative discussions, resulting in limited scientific guidance and support for the conservation practices. Therefore, this study aims to provide empirical evidence and scientific reference for achieving common welfare in Chinese national parks by proposing a comprehensive indicator framework.

Methods: This study draws on three dimensions, owned by all, participated by all, and shared by all, and proposes 15 common welfare indicators. Using questionnaire surveys and methodologies such as linear discriminant analysis and hierarchical regression analysis, a quantitative assessment of common welfare was conducted based on the perceptions of stakeholders in the Giant Panda National Park (GPNP).

Results: The results showed that the overall common welfare in the GPNP was generally perceived positively. However, perceptions varied among stakeholder groups: local management agencies and governments held the most positive views, local communities had the most negative perceptions, while local enterprises, experts, and visitors maintained a neutral stance.

Conclusion: To achieve common welfare, increased attention should be directed toward the local communities. In particular, comprehensive promotion of community co-management and improvement of the ecological compensation mechanism are essential. Furthermore, enhancing communication among stakeholders and optimizing their participation are crucial steps in this process.@en