Answer:
ok this is point less but whatever you want
Answer:
Because the biodiversity decreases.
Explanation:
An ecosystem is richer when it has a higher biodiversity, remember that each living thing has an specific role in the food web. When in an ecosystem this web is bigger, increases the probability of sustain a living thing. For example, in the sea, if there is a fish, this is going to be more probabilities of survive if this fish can eat different plants or other fish. But if in the ecosystem there are not a variety of them, it probability to survive is less if one of it food desapear.
I'd say probably Biomass, not 100% sure but it's renewable, but it can create power and heat.