SBS - AAP
Global warming could outstrip the ability of grasses, including wheat, corn and rice to adapt, leading to crop failures and mass starvation, say scientists.
Global warming could rapidly threaten grasses including staple
foods such as wheat and rice that provide half of all the calories
consumed by humans, say scientists.
A new study looking ahead to 2070 found that climate change was
occurring thousands of times faster than the ability of grasses to
adapt.
While the research cannot predict what might happen to world food
supplies as a result, the authors warn of "troubling implications".
Grass is food, both for many species of animals and humans.
Wheat, rice, maize, rye, barley and sorghum are all edible grasses
that yield nutritious grains. In many parts of the world and throughout
history, wheat or rice famines have led to widespread starvation.
The new research, published in the Royal Society journal Biology
Letters, looked at the ability of 236 grass species to adapt to new
climatic niches - the local environments on which they depend for
survival.
Faced with rapid climate change, species wedded to a particular niche
can survive if they move to another region where conditions are more
suitable, or evolve to fit in with their altered surroundings.
The scientists found that the predicted rate of climate change was
typically 5000 times faster than the estimated speed at which grasses
could adapt to new niches.
Moving to more favourable geographical locations was not an option
for a lot of grass species because of limits to their seed dispersal and
obstacles such as mountains or human settlements.
The researchers, led by Dr John Wiens, from the University of Arizona
in the US, wrote: "We show that past rates of climatic niche change in
grasses are much slower than rates of future projected climate change,
suggesting that extinctions might occur in many species and/or local
populations.
"This has several troubling implications, for both global biodiversity and human welfare.
"Grasses are an important food source for humans (especially rice,
wheat and corn). Evolutionary adaptation seems particularly unlikely for
domesticated species ... and even local declines may be devastating for
some human populations."
Links
No comments :
Post a Comment