Thermal tolerance in Neotropical savanna tree species: exploring the temperature dependencies of photosynthesis in a diverse biome

Summary

The Brazilian Cerrado is one of the world's largest and most diverse savannas. However, the region has become hotter and drier in the past decades, which may push plant species to their thermal limits. Therefore, this study aimed to investigate the temperature response of photosynthetic apparatus in Cerrado species, focusing on leaf-level photosynthesis dynamics and leaf nutrients. The survey covered species in two opposite regions of the Cerrado with contrasting climatic conditions, including widely distributed species (occurring in both regions) and those restricted to each region. As a result, regardless of region or distribution range, species showed no difference in the acclimation of photosynthesis components. Instead, the study species used leaf nutrition acclimation strategies to improve their performance at upper thermal limits. This study also proposed a faster approach for assessing the temperature dependence of leaf photosynthetic capacity, advancing our understanding of global species' thermal tolerance.