Not only did Hurricane Katrina devastate cities and imperil lives, it also wreaked havoc on the environment. An article in the Washington Post describes a recently published study of ecological losses from the 2005 hurricane.
What scientists found, after examining satellite images of the affected areas, was that approximately 320 million trees were killed or damaged in the hurricane. Many trees that sustained injuries in the hurricane's winds or were exposed to standing water died shortly after the storm.
Also of note:
Chambers [the study's lead author] was even more surprised when his team calculated how much carbon will be released as the storm-damaged vegetation decomposes. The total came to about 100 million tons, equal to the amount that all the trees in the United States take out of the atmosphere in a year.
A short presentation on the NASA site, called "In Katrina's Wake," also summarizes the study's findings.
Links:
"Katrina, Rita Caused Forestry Disaster" (The Washington Post)
"Hurricane Katrina's Carbon Footprint on U.S. Gulf Coast Forests" (Science magazine; subscription or payment required to view full article)
Photos: Pre- and post-Katrina satellite images. Visible are the twin bridges over Lake Pontchartrain, east of New Orleans. Bayou Sauvage National Wildlife Refuge is the large green area toward bottom of left photograph. The same area—in red in the photograph on the right—indicates extensive tree mortality. Courtesy of the U.S. Geologic Survey.

