The team's research also shows that most known ice-nucleating bacteria are associated with plants and some are capable of causing disease.
"Bacteria have probably been around for a million years," Sands said. "They live on the surface of plants, and may occasionally cause plant disease. But their role in rain-making may be more important."
Indeed, the implications of a relationship between rain and bacteria could be enormous, though they are yet to be proven, Sands said.
For example, a reduced amount of bacteria on crops could affect the climate. Because of the bio-precipitation cycle, overgrazing in a dry year could actually decrease rainfall, which could then make the next year even dryer.
"Drought could be less of a problem once we understand all of this," Sands said.
Sands, who earned a doctorate in pathology and bacteriology from the University of California-Berkeley, proposed the concept of bio-precipitation approximately 25 years ago, but few people believed him.
Since that time, he said, better tools have changed the research climate, because new DNA technology allows researchers to distinguish the bacteria, and giant computers allow people to do meteorological studies with satellites.
"It's fun to see something come out after 25 years," Sands said, "particularly when we knew back then it was true."
More studies must be done, though, because questions remain. For example, since the bacteria do not grow above 84 degrees, precipitation could be affected if the world's weather creeps up and reaches a cut-off point, Sands said. The researchers are also examining the bacteria to find out if they vary by region.
At any rate, a diverse group of people should be interested in the res
|Contact: David Sands|
Montana State University