Answer :
Keystone species are crucial for maintaining the biodiversity and structure of an ecosystem, often by keeping other species' populations in check. They are not, however, always the first to colonize an area. Thus, the statement "Keystone species are always the first to colonize an area" is incorrect.
A keystone species is one whose presence is key to maintaining biodiversity in an ecosystem and to upholding an ecological community's structure. These species can have a disproportionate impact on their ecosystems. However, they are not necessarily the first to colonize an area.
So, the correct answer is: "Keystone species are always the first to colonize an area."