Demonstrating the benefits of biodiversity Demonstrating the benefits of biodiversity Experiments on a controlled micro-ecology confirm current thought on the importance of biodiversity. Now, University of Minnesota ecologists, working with communities of microbes, have shown that having more species at each level such as green plants, decomposers, herbivores and predators improves the reliability of ecosystem functioning. The research supports the idea that preservation of a diversity of species is important, even if certain species appear to have no direct benefit to humans. In the research, Shahid Naeem, assistant professor of ecology, and graduate student Shibin Li filled petri dishes with single-celled green algae, which performed photosynthesis to provide basic food for Naeem's tiny ecosystems.
Ecologists call such organisms primary producers.
The researchers then added bacteria whose function was to decompose the algae and other dead matter. They also added microbes such as amoebae and paramecia, which acted as consumers of the algae and each other. With these three functional groups producers, decomposers and consumers represented, the researchers varied the number of species in each group and watched for 57 days. They maintained replicates of each ecosystem under two levels of light and three levels of nutrients to ensure that the results were due to interactions among organisms, not to specific levels of nutrients or energy. At the end of the experiments, the researchers found that the amount of green algae was most predictable in those dishes that had the highest number, namely three, species in each functional group.