Question

what are the defining features of a keystone species?
keystone species colonize newly exposed habitats and are promoters of early succession.
a keystone species is particularly vulnerable to changes in its ecosystem.
keystone species impact the ecological community to a greater extent than their population numbers would suggest.
many species depend on keystone species for unique ecological services that they provide.
keystone species inhabit core areas of ecosystems and are niche specialists.

Explanation:

A keystone species has a disproportionately large impact on its ecological community relative to its abundance. Other species often rely on the unique ecological services it provides. Colonizing newly - exposed habitats is more characteristic of pioneer species. High vulnerability is not a defining feature of keystone species. Niche specialization and inhabiting core areas are not the main defining features.

Answer:

• Keystone species impact the ecological community to a greater extent than their population numbers would suggest.
• Many species depend on keystone species for unique ecological services that they provide.