Based on a press release by the University of Waikato, New Zealand

Healthy ecosystems depend on more than just having lots of species – they rely on the complex relationships between plants, prey and predators, according to new international research led by the University of Waikato and the German Centre for Integrative Biodiversity Research (iDiv).
Published in the journal Nature, the study found that ecosystems with greater diversity of species – and particularly a greater diversity of predators – function more effectively, helping maintain natural processes that people rely on, such as pest control, climate regulation and ecosystem stability.