Complex sentence: By contrast, top-down processes are those in which predators limit the biomass of species at lower trophic levels through consumption; in the absence of predation, these lower level species would flourish because the resources that support their energetic requirements are non-limiting.
Split into simpler sentences: By contrast, in top-down processes, predators limit the biomass of species at lower trophic levels through consumption. In the absence of predation, these lower level species flourish because resources that support their energetic requirements are non-limiting.