According to the prevailing opinion, species-rich ecosystems are more stable against environmental disruptions such as drought, hot spells or pesticides. The situation is not as simple as it seems, as ecologists have now discovered that under certain environmental conditions, increased biodiversity can also lead to an ecosystem becoming more unstable.

    The scientists specifically researched how biodiversity affects the stability of ecosystems. As model organisms, they used six species of ciliates tiny protozoans that live in water. The researchers put varying numbers and combinations of these ciliates in sample vials, thereby creating miniature ecosystems that they then let thrive at temperatures between 15 and 25 degrees Celsius. The researchers then used novel video evaluation techniques to analyze how stable the biomass production in these small ecosystems was.

    High biodiversity simultaneously furthers and hinders the stability of an ecosystem. In other words, more diverse the species community in miniature ecosystems then less was the biomass production that fluctuated regardless of temperature. At higher temperatures, however, the researchers found that protozoans produced less biomass the more species were bustling about the system.

Fig: As model organisms six species of ciliates were used tiny protozoans that live in water.
Image credit: University of Zurich (UZH).

Source: www.sciencedaily.com