yes, coral polyps are a keystone species. it would be a keystone species because it is important in order for the coral to thrive.
Yes, because even though other trees produce more oxygen, the small trees will still produce some oxygen. On top of this there are more small trees than big trees, so even though they make less oxygen, in whole they end up making more when added together!
<span>They receive more direct sunlight than other regions.</span>
