Niches are a somewhat abstract concept defined in different ways. The sum of the requirements of an organism. The role an organism plays in the ecosystem. In general, the more niches there are, the more species that can coexist in a particular area. Further, the more vertical and horizontal stratification that exists, the more habitats, niches, and possible species are possible.
Temporal components can create more niches.
Trophic components can also create more niches. These can include browsers and grazers in a common habitat, or differences in type of food consumed by young and old animals, for example. Because competition often keeps the numbers of individuals below the carrying capacity, more niches may be available in a particular community. Interspecific competition usually doesn't lead to competitive exclusion. Small to moderate amounts of disturbance can create more niches.