Biology · BIODIVERSITY AND CONSERVATION

In David Tilman's long-term ecosystem experiments using outdoor plots, which of the following observations was confirmed regarding community stability?

1. A
   Plots with more species showed greater year-to-year variation in total biomass.
2. B
   Increased diversity contributed to higher productivity and less year-to-year variation in biomass.
3. C
   Species richness had no measurable correlation with total biomass or disturbance resistance.
4. D
   Higher species richness consistently caused lower primary productivity.