What are ways that pioneer species differ from climax communities? Check all that apply.

a. Pioneer species occur only in primary succession, while climax communities occur in both types of succession.
b. Pioneer species inhabit volcanic islands, while climax communities occur on continents.
c. Pioneer species include only one or two species, while climax communities include many species.
d. Pioneer species reproduce in small numbers, while climax communities reproduce in large numbers.
e. Pioneer species tend to be small and simple, while climax communities tend to be larger and more complex.