Biodiversity equals stability?
Results from ecological experiments in 1993 and 1994 also found that levels of biodiversity significantly affected an ecosystem's resistance and recovery to drought. An eleven year study of native grassland ecosystems in Minnesota, which included the worst drought seen in that area in fifty years, found that ecosystems with high amounts of species suffered significantly less loss of species and recovered much more rapidly than those areas with fewer taxa.
The theory behind this is that individuals of a single species will compete for the same resources, particularly space. Individuals of different species can take advantage of different spatial territory and resources.