Scientists at Guelph University in Ontario warn against a reliance on seemingly stable but vulnerable single-crop monocultures, a failure of which risks sudden ecosystem disturbances.
Maintaining biodiversity by having lots of species in an area helps ecosystems avoid irreversible collapse after human disturbances such as climate change or pest invasion, they said.
"Species are more important than we think," biologist Andrew MacDougall said in a university release Wednesday. "We need to protect biodiversity."
A monoculture stand of trees or crops might appear stable and productive, he said, but it's an ecosystem that is more vulnerable to collapse.
The researchers studied longstanding pasture grasslands on southern Vancouver Island for 10 years, selectively burning plots to compare the impact in areas of mostly grasses with areas of mixed grasses and diverse native plants.
Seemingly stable grassland plots collapsed in one growing season and were subsequently invaded by trees, they found, while more diverse sites resisted woody plant invasion.