Spread of woody plants highlights far-reaching impacts of climate change
As the climate continues to warm it is changing the natural environment in all kinds of ways, from "death events" on the Great Barrier Reef to the growth of vegetation in the upper reaches of the Himalayas. A massive study has now revealed global warming is also prompting the spread of wooded plant coverage on the world's savannas and tundras, which spells bad news for the environment.
The research was led by scientists at the University of Edinburgh and is described as the "largest global woody cover change study of its kind to date." It involved looking at more than 1,000 records of woody plant cover from 899 sites in six different continents, along with temperature and rainfall data, to ascertain how climate change is driving shifts in the landscape. This analysis also accounted for the role wildfire and animal grazing patterns play in these transformations.
According to the team, the Arctic tundra that stretches across Canada, the US, Greenland, Europe and Russia, features 20 percent more shrub coverage than 50 years ago. Shrub and tree coverage in the world's savannas, which feature in Australia, the plains of Africa and in South America, increased by 30 percent in the same timeframe.
These savannas and tundras make up around 40 percent of the world's land mass. Because wooded plants store carbon, serve as fuel for fires and negatively affect how much of the sun's heat is reflected back into space, the scientists believe these profound changes to the landscapes could have a significant impact on the global climate and concentrations of carbon in the atmosphere.
On a more local level, the changes could influence the biodiversity in these regions, while expanding shrub coverage could cause soil temperatures to rise. This could have profound impacts on the permafrost that lies beneath the tundras, which contain huge amounts of carbon that would be released into the atmosphere were it to thaw.
"This research indicates the far-reaching effects of climate change across the planet," says Mariana García Criado from the University of Edinburgh's School of GeoSciences. "Uncovering the ways in which different landscapes are responding requires collaboration among scientists, and cooperation with local peoples to better understand the changes we’re seeing and their impacts from different perspectives."
The research was published in the journal Global Ecology and Biogeography.
Source: University of Edinburgh