Weeds set to take over world

20:49, Feb 18 2009

Weeds could soon take over the world, because they are more likely to survive climate change, a new study has found.

A report by Sydney's Botanic Gardens Trust says few plants are versatile enough to flourish after dramatic changes in their environment.

"As habitats change in response to climate change, the species that are most likely to survive are those with short life cycles that can adapt quickly and those that are readily dispersed, common characteristics of most weed species," the trust's senior botanist Peter Weston said.

The trust's researchers monitored 11,000 plant species across six continental landmasses and "traced the evolution of characteristics of plants from these different regions".

The study found many species would have difficulty adapting as their natural habitats shrank due to climate change, and biodiversity would be lost.

"We were struck by the conservatism of plants, basically how rarely they were able to adapt and flourish outside of their ancestral environments," Dr Weston said in a statement.

"Conservationists can't expect plants to dramatically change their ecological preferences and evolve to fit new habitats as the boundaries of these biomes change in response to climate change."