The phoenix flora: plant survival, succession, and putative adaptation in the post-atomic landscapes of Hiroshima and Nagasaki

The atomic bombings of Hiroshima and Nagasaki in 1945 created a unique environment of acute, high-dose ionizing radiation, contrasting sharply with the chronic low-dose rate exposure in the Chernobyl and Fukushima Exclusion Zones. This stands in stark contrast to the chronic, low-dose rate contamination that defines the Chernobyl and Fukushima Exclusion Zones. While the long-term ecological effects of the latter are well-documented, a systematic synthesis of the floral response to the atomic bombings is lacking. This review integrates historical data with modern radio-ecological principles to analyze plant survival and succession. We document the remarkable recovery of vegetation, from the resprouting of survivor trees, the hibakujumoku, such as Ginkgo biloba trees, to the role of soil seed banks. We propose that this recovery was driven by constitutive resilience, relying on pre-existing traits such as robust DNA repair, antioxidant capacity, and protective morphology, rather than the multi-generational genetic adaptation observed in chronic exposure zones. By framing these events against the backdrop of Chernobyl and Fukushima, this review demonstrates how the nature of the radiological insult dictates fundamentally different ecological and evolutionary outcomes. The flora of Hiroshima and Nagasaki thus serves as a critical case study of extreme instantaneous stress tolerance. We conclude by proposing a future research agenda that employs advanced genomic tools on these living archives to uncover the mechanistic basis of their survival, thereby integrating a pivotal historical case into a holistic understanding of plant persistence in radically altered environments.