Why do heavy metals tolerant plants in rare in areas?

Heavy metals tolerant plants are rare in areas contaminated with heavy metals because such environments often create extreme stress conditions that challenge plant survival and growth. These plants must possess specific adaptations, such as mechanisms for sequestering or detoxifying metals, which can take time to evolve. Additionally, the high toxicity of heavy metals can limit biodiversity, reducing the number of species that can thrive in these areas. Consequently, the combination of environmental stressors and evolutionary pressures results in a scarcity of heavy metals tolerant plant species.