科学美国人60秒:Climate Change Alters Soil Bacteria Distribution

When we think about global warming, we tend to fret about things we can see: plants, animals, the polar ice caps. But the effects of climate change may go much deeper: into the earth itself. Because a new study shows that temperature controls where soil-dwelling microbes live. The findings are in the journal Science. [Ferran Garcia-Pichel et al., Temperature Drives the Continental-Scale Distribution of Key Microbes in Topsoil Communities] (Audio of Garcia-Pichel here.)

Bacteria are key players in the formation of topsoil. They add carbon and nitrogen, and extract nutrients. Uprooting these microscopic residents could upset the land’s fertility and lead to soil erosion.

To investigate how a rise in temperature might alter bacterial distribution in different desert climes, researchers surveyed the microbes present in a pinch of crust from several arid locations. And they found that cooler deserts are ruled by one type of bacteria, and warmer ones are dominated by another.

If the climate models are correct, 50 years from now the heat-seeking bugs will have elbowed out those that prefer life a bit more chilly.  What this microbial coup will do to the planet’s ecological health is not known. But the results suggest that scientists interested in climate change need to dig in, because global warming is more than skin deep.

—Karen Hopkin