As Biodiversity Declines, Disease Flourishes

[phantom power]

The studies cited showed that even if the density of the species that play hosts to the pathogens —say, white-footed mice in the case of Lyme disease and snails in the case of schistosomiasis — remains the same, the spread of disease is less likely in an environment with a greater variety of species.

The white-footed mouse is in many ways the Typhoid Mary of Lyme disease, suffering little from any infection itself but readily infecting all the deer ticks that feed on it. Opossums play a different role.

Opossums, native to North America, are “poor hosts for the pathogen, kill the vast majority of ticks that attempt to feed on them and are absent from many low-diversity forest fragments and degraded forests where mice are abundant,” the authors write.

Suburban development that reduces forests to small patches tends to have little effect on the mice, the best hosts for the Lyme bacterium, but tends to drive away opossums, which serve as buffers against the disease.

http://green.blogs.nytimes.com/2010/12/02/as-biodiversity-declines-disease-flourishes/

[pscot]

1. Remove all the large predators

and the small ones try to take up the slack.