→ For many decades, ecologists believed that communities with more species, generally, tend to be more stable than those with less species.
→ A stable community should not show too much variation in productivity from year to year; it must be either resistant or resilient to occasional disturbances (natural or man-made), and it must also be resistant to invasions by alien species.
→ We don't know how these attributes are linked to species richness in a community, but David Tilman's long-term ecosystem experiments using outdoor plots provide some tentative answers.
→ Tilman found that plots with more species showed less year-to-year variation in total biomass.
→ He also showed that in his experiments, increased diversity contributed to higher productivity.
→ Rich biodiversity is not only essential for ecosystem health but imperative for the very survival of the human race on this planet.
→ Biodiversity contributes to many important ecological services.