Question

the vast species diversity in rain forest indicates that these forest ?

Answer 1

Have Many Niches

Answer 2

It indicates a variety of things - for which we need the options that you have to chose from

One of the most interesting for me (perhaps because it is counterintuitive and exactly opposite what I'd have hypothesised) things about the rain forests is that their enormous biodiversity evolved because the 'geo-diversity' or variation in the soil, rocks, wind and climate and other 'physical' characteristics is basically nil.

This homogeneity imposes incredible selective pressures on the organisms that live on this environment, meaning there are big rewards in terms of survival for even very small changes in morphology or action, which favours bio diversity.