Final answer:
The false statement about keystone species is that they typically have low ecological importance and limited influence on the ecosystem. Keystone species actually play a critical role in maintaining ecosystem structure and biodiversity, and their loss can lead to significant ecological changes.
Step-by-step explanation:
Of the statements about keystone species provided, the one that is false is 'keystone species typically have low ecological importance and limited influence on the ecosystem.' In fact, keystone species have a disproportionately large influence on their ecosystems relative to their abundance. Keystone species maintain the structure and biodiversity of their ecosystems, and their removal can lead to significant changes or decline in ecosystem health. For example, the reintroduction of wolves to Yellowstone increased biodiversity by altering the populations of elk, coyotes, and carrion eaters. It's also incorrect to assert that a keystone species will always be at the top of the food chain, as this is not a defining characteristic of keystone species. Moreover, the impact of removing a keystone species does not always lead to the 'immediate collapse' of the ecosystem, though it can cause significant disruptions over time. Lastly, the statement that a species must act as a keystone species in all parts of its range is also false; the role of a keystone species can vary geographically.