Write the importance of species diversity to the Exosystem. Support your answer with the finding of Tilman.

Explanation

(i) Ecologists for many years, believed that communities with species are more stable than those with less species.
(ii) A stable biological community does not show too much variation in production from year to year. It must be resistant or resilient to occasional disturbance and must also be resistant to invasions by alien species.
(iii) David Tilman's long term ecosystem experiments using outdoor plots provided answers to stability of a biological community and species richness in that community.Tilman found that plots with more species showed less year-to-year variation in total biomass. He also showed in his experiments that increased diversity contributed to higher productivity.