What happens as the number of niches in an ecosystem goes up?

Which two following best identify the central themes of this speech in the passage the man in the arena

Plz answer ! find the alps. what countries and country borders intersect this major mountain range? which borders seem to be defined by the edges of the mountains? which borders seem to be defined by the edges of the mountains? which borders cut across the mountains?

What geologic process is related to caldera formation?