Study helps clarify role of soil microbes in glob...(t in a handful of dirt there are somewhe...)
t in a handful of dirt, there are somewhere around 10,000 species and millions of individual bacteria and fungi," said study co-author Matthew Wallenstein, a research scientist at Colorado State University. "Our findings add to the understanding of how complex these systems are and the role they play in feedbacks associated with climate change."
The researchers studied soil microbes at Harvard Forest in Massachusetts, the site of a soil warming experiment that began in 1991. Scientists took soil samples from two plots, one in which buried cables heat the soil to five degrees Celsius above the ambient soil temperature (a condition that is expected to occur around 2100) and a control condition in which cables are buried but not producing heat.
In the first set of experiments, the scientists compared microbial respiration in the two groups and found lower rates of decomposition in the heated plots. This finding supported the idea that respiration decreases after a few years of warming, but didn't explain whether the cause was substrate depletion in the warmer soils or adaptation by the microbes.
In the next set of experiments, they added the simple sugar sucrose to both sets of soils to alleviate any food limitation for the microbes. They found that microbes from both conditions increased their respiration, but that the increase was greater in the unheated control soils than in the heated soils. "That finding told us that substrate depletion played a role," Bradford said, "but it also told us that there were other factors involved."
The researchers then measured microbial biomass and found that there were fewer microbes in the heated soils. To test whether thermal adaptation occurred, they measured respiration while keeping temperature constant. They found that respiration rates were indeed lower in the heated versus the control soils, even when adjusting for microbial biomass.
Wallenstein pointed out that the study is among
'/>"/>
| Contact: Sam Fahmy sfahmy@uga.edu 706-542-5361 University of Georgia Source:Eurekalert |
Related biology news :
1. Childhood obesity indicates greater risk of school absenteeism, Penn study reveals
2. A study by the MUHC and McGill University opens a new door to understanding cancer
3. Study begins to reveal clues to the cause and progression of sepsis
4. Clones on task serve greater good, evolutionary study shows
5. New study warns limited carbon market puts 20 percent of tropical forest at risk
6. New study examines how rearing environment can alter navigation
7. Study links cat disease to flame retardants in furniture and to pet food
8. New continent and species discovered in Atlantic study
9. Study shows link between alcohol consumption and hiv disease progression
10. Feeling hot, hot, hot: New study suggests ways to control fever-induced seizures
11. Study finds environmental tests help predict hospital-acquired Legionnaires disease risk
| Copyright © 2003-2009 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |