Cutting edge study show the importance of diversity essential for healthy planet ecosystems. Excerpt from Science Daily:

“Zavaleta and two ecologists who recently received Ph.D.s from UCSC illustrate the importance of landscape diversity in their article “Several scales of bioversity affect ecosystem multifunctionality” published this week in the Proceedings of the National Academy of Sciences.
Lead author Jae R. Pasari, who received his Ph.D. in 2011, conceived of the study for his dissertation. He, Zavaleta, and coauthor Taal Levi created simulations based on landmark research conducted by David Tilman, professor of ecology, evolution, and behavior at the University of Minnesota.
Tilman — also a co-author — created 168 plots nine meters square and planted them with randomized combinations of perennial grassland species. He was interested in how the plots would fare depending on the combination of species included.
Pasari, Levi, and Zavaleta took Tilman’s data gathered since 1997 to create 7,512 experimental computerized landscapes. The computer simulations are grounded on very real data, Zavaleta said.
“We used the simulation models to create imaginary landscapes with many kinds of habitats,” she said. The team was able to test combinations of “patches” in order to determine the overall potential health of the “quilt.”
The authors write: “In addition to conserving important species, maintaining ecosystem multifunctionality will require diverse landscape mosaics of diverse communities.”
“What’s new here,” Zavaleta says, “is reminding us that it’s not just important to protect a diversity of species but also important to protect the mosaic of habitat patches in a landscape.”

http://www.sciencedaily.com/releases/2013/06/130607160335.htm