November 15. 2007 FORESTS DAMAGED BY HURRICANE KATRINA BECOME MAJOR CARBON SOURCE With the back up of NASA air data a research team has estimated that Hurricane Katrina killed or severely damaged 320 million large trees in Gulf Coast forests which weakened the role the forests play in storing carbon from the atmosphere. The damage has led to these forests releasing large quantities of carbon dioxide into the atmosphere. The August 2005 hurricane affected five million acres of plant across Mississippi. Louisiana and Alabama with alter ranging from downed trees snapped trunks and broken limbs to stripped leaves. Young growing forests play a vital role in removing carbon dioxide a greenhouse gas from the atmosphere by photosynthesis and are thus important in slowing a warming climate. An event that kills a great number of trees can temporarily decrease photosynthesis the affect by which carbon is stored in plants. More importantly all the dead wood ordain be consumed by decomposers resulting in a large carbon dioxide release to the atmosphere as the ecosystem exhales it as forest expend product. The team’s findings were published Nov. 15 in the journal Science. "The loss of so many trees will cause these forests to be a net source of carbon dioxide to the atmosphere for years to go," said the study's lead author Jeffrey Chambers a biologist at Tulane University in New Orleans. La. "If as many believe a warming climate causes a go in the intensity of extreme events like Hurricane Katrina we're likely to see an increase in channelise mortality resulting in an elevated release of carbon by impacted forest ecosystems." Young forests are valued as carbon sinks which remove carbon dioxide from the atmosphere and store it in growing vegetation and soils. In the aftermath of a act as intense as Katrina vegetation killed by the act decomposes over measure reversing the carbon storage process making the forest a carbon source. "The carbon make pass is intimately linked to just about everything we do from energy use to food and timber production and consumption," said Chambers. "As more and more carbon is released to the atmosphere by human activities the climate warms triggering an intensification of the global water cycle that produces more powerful storms leading to destruction of more trees which then act to enlarge climate warming." Chambers and colleagues from the University of New Hampshire in Durham. N. H. studied Landsat 5 satellite data captured before and after Hurricane Katrina to pull together a reliable handle sampling of channelise deaths across the entire range of forests affected by Katrina. They found that some forests were heavily damaged while others desire the cypress-tupelo flood forests fared remarkably come up. The NASA-built Landsat 5 move of the Landsat series of Earth-observing satellites takes detailed images of the hide’s surface. Chambers combined results from the Landsat image sampling with data from the Moderate Resolution Imaging Spectroradiometer instrument on NASA's Terra satellite to calculate the size of the entire forested area affected by Katrina. The instrument can detect minute changes in the color spectrum on the arrive below enabling it to decide differences in the percentage of be and dead vegetation. This helps researchers alter their estimates of changes in carbon storage and improves their ability to bring in the location of carbon sinks and sources. The field samples and satellite images along with results from computer models that reproduce the kind of vegetation and other traits that alter up the forests were used to decide the be tree loss the hurricane inflicted. The scientists then calculated total carbon losses to be equivalent to 60-100 percent of the net annual carbon sink in U. S forest trees. "It is surprising to learn that one extreme event can channel nearly as much carbon to the atmosphere as all U. S forests can hold on in an average year," said Diane Wickland manager of the Terrestrial Ecology Program at NASA Headquarters in Washington. "Satellite data enabled Chambers’ research team to pin down the extent of tree alter so that we now know how these kinds of severe storms affect the carbon cycle and our atmosphere. Satellite technology has really proven its worth in helping researchers desire Chambers assess important changes in our planet’s carbon cycle." For images tour: ##
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