CLEMSON--Hurricanes, even ones as powerful as Hugo, are a necessary and important part of the natural order of things. While they may destroy some man-made structures and wildlife habitats, hurricanes also create new habitats for wildlife and break long, hot summer droughts, giving crops a much-needed drink of water ... if the crops aren't blown away by the wind.
"Only now are scientists beginning to recognize the critical importance of natural catastrophes in ecosystem dynamics," said William H. Conner, a Clemson University forestry scientist who is studying the effects of hurricanes on coastal environments in South Carolina and Louisiana.
Conner is based at Clemson's Belle W. Baruch Institute of Coastal Ecology and Forest Science in Georgetown; other Clemson forest scientists are located at the main campus or at one of the university's four other public service research centers around the state. Hurricane Hugo's sweep through South Carolina served as a living laboratory for forestry and environmental scientists from the U.S. Forest Service, S.C. Forestry Commission and other Southeastern universities, as well as Clemson.
"We will be much better prepared to respond to forest disasters because of Hugo," said Roy L. Hedden, a Clemson forest resources scientist. "Now we know how many people and what equipment it takes to salvage the downed timber, what timber is salvageable, how to store the timber and how to rehabilitate the remaining forest."
Nearly two-thirds of South Carolina (12.5 million acres) is forest land --either public forests, privately owned land or production timber plantations. Before Hugo came ashore, the S.C. Forestry Commission warned forest landowners to expect major damage.
The day after the storm passed through the state, with reported sustained winds of 121 miles-per-hour and reported gusts up to 147 miles-per-hour, a forest disaster was declared. More than one-third of the state's forest land (4.5 million acres) was damaged by the high winds and a tidal surge up to 20 feet above sea level that swept saltwater inland. Hugo affected a larger area and downed more timber than any previous natural catastrophe in the United States-- more than Hurricane Camille (1969), Mount Saint Helens (1980) and the Yellowstone fires (1988) combined.
"Hugo damaged more than $1 billion of timber and destroyed valuable wildlife habitat across 23 of the state's 46 counties," said Thomas J. Straka, a Clemson forest resources scientist.
A Governor's Forest Disaster Salvage Council was convened to coordinate salvage efforts for the damaged timber. Loggers and equipment were called in from neighboring states. Salvage workers used every type of equipment-- from mules to helicopters-- to remove the timber. Some of the logs were stacked in piles 10-25 feet high and then soaked with irrigation sprinklers to protect them from damage by fungus or insects.
In spite of the heroic efforts, only about 15 percent of the damaged wood could be salvaged because of the hazardous working conditions and the extent of the damage. Much of the higher quality wood that would normally be used as construction lumber had to be processed (at a lower value) as pulpwood because of extensive damage to the trunks. Timber prices first dropped because of the glut produced by the hurricane, then rose as the supply of salvaged timber was depleted.
About one-quarter of the affected area, 1.2 million acres, required reforestation because of the extensive damage. This land was primarily held by private landowners who did not actively manage their forests to keep trees in optimum condition. The federal government provided $5 million to promote reforestation and provide technical assistance in the effort.
In addition to the direct damage caused by the wind, there was extensive damage from a surge of seawater that was pushed into inland freshwater systems by the winds. "The storm surge moved into the Hobcaw Forest at 10 feet above sea level," said Thomas M. Williams, a Clemson forest hydrologist based at the Baruch Institute near Georgetown. "The saltwater killed practically the entire forest in the low-lying areas that retained seawater as long as a month after the surge receded."
The deepest storm surge was seen at McClellanville where it reached 20 feet above sea level. After the winds and saltwater subsided, researchers noted a virtual absence of insects and wildlife in the surge-affected forest. Flying insects and birds were the first to return; but six months after Hugo, the number of reptiles and amphibians remained significantly lower than before the storm.
One of the hardest hit areas was the Santee Experimental Forest in the Francis Marion National Forest north of Charleston. This area received the full brunt of the strongest winds, called the eyewall because they surround the eye of the hurricane. Before Hugo, the Santee Forest housed 477 colonies of endangered red-cockaded woodpeckers. After the storm, only 100 family groups could be found. Forest salvage operations included drilling new nesting cavities for the birds.
"One of the risks of current methods of protecting rare and endangered species by confining them to a few protected areas is that the destruction of one such area can severely damage an entire population," said Allan P.C. Marsinko, a Clemson forest resources scientist.
While destroying habitats for some species, the storm improved habitats for others. For example, the downed trees created open spaces for new plant growth for deer herds and increased insect populations for wild turkeys.
"Nature abhors a vacuum," said Charles A. Gresham, a Clemson forest ecologist who has tracked the recovery process since Hugo hit. "Within 10 years, we have seen significant recovery-- back to a fully functional, productive forest with a lot of habitat for wildlife."
The only remaining evidence of Hugo today is the debris of larger fallen trees and logs that now provide habitat for wildlife and support the growth of other plants by releasing nutrients into the soil. Three species of trees weathered the hurricane with less damage than others. Not surprisingly, they are the trees most closely identified with the Lowcountry's coastal plain: live oak, cypress and longleaf pine.
Clemson's public service research is funded through the university's Agriculture and Forestry Research System.