The biological significance of keystone species in ecosystems is profound, as they play a critical role in maintaining the structure and stability of their environments. Keystone species have disproportionately large effects on their ecosystems relative to their abundance, often influencing community composition and biodiversity. Their activities, such as predator-prey interactions or habitat modification, can regulate populations and promote diversity among other species. Protecting keystone species is vital for preserving ecological balance and ensuring the health and resilience of entire ecosystems.