Losing species makes ecosystems sick

2019-03-07 14:09:00

TREE-HUGGERS are fond of saying that the planet is sick – and they may be onto something. The huge drops in biodiversity in recent decades could cause increases in disease. Felicia Keesing of Bard College in Annandale, New York, and her colleagues reviewed 15 diseases of plants and animals and found that for 13, contagion increased when biodiversity fell (Nature, vol 468, p 647). Resilient “weed” species that survive where other species might not, such as mice and ryegrass, also happen to be the best reservoirs for infection, Keesing’s team found. She believes this is because weed species tend to live fast and die young,