LAWRENCE, Kans. -- In 1993, Science magazine estimated that 100,000 to 165,000 square kilometers of tropical rain forests are lost to deforestation annually - clear-cutting of native forests.
That's an area roughly equal to half the state of Kansas.
So when Valery Terwilliger, assistant professor of geography at the University of Kansas, talks about deforestation in Central and South America, she makes her point quickly.
"There are now many regions where we can stop asking the question, 'Is all this deforestation going to have an impact?' Local people know there is an impact," Terwilliger said. "We need to try to answer the question, 'To what extent can we recover the losses?'"
Terwilliger is hoping her research on plant tissues and plant growth in Central America will help developing countries start a reforestation trend and possibly turn the native plant life into a profitable resource.
"In the countries where I have worked, such as Panama, Nicaragua and Costa Rica, there is a real concern that they have overextended themselves in deforestation," she said.
Terwilliger believes that if countries realize they need trees for growth and survival, they can capitalize on native species and return the cleared land back to its native foliage.
Terwilliger starts her research on a species by obtaining specimens in the rain forest and then examining them in a KU lab to analyze the stable isotopes in the plant tissues.
The research shows how well plants are using carbon dioxide and water in tropical forests that are normally inaccessible to measurement.
The lab is a facility to analyze stable, or nonradioactive, isotopes of carbon, oxygen and hydrogen. The research shows how well plants are using carbon dioxide and water in tropical forests that are normally inaccessible to measurement.
"I am interested in the ranges of environments that trees of a similar species can occupy."
The lab was developed with a grant from the National Science Foundation's Experimental Program to Stimulate Competitive Research through the Kansas Science and Technology Advanced Research program.
"In some countries there were incentives to cut down the forests and convert them to pine and eucalyptus growth," she said. "When that didn't work, they turned the land to pasture."
Pine and eucalyptus trees are not necessarily native to tropical regions. They are usually used to reforest regions where they don't occur naturally.
According to Terwilliger, some officials were hoping to cash in on pulp and paper needs by planting the exotic trees. However, the plan didn't bear fruit.
"The exotic species of trees need a lot more work and expense to keep them healthy," she said. "So it isn't any more cost-effective to grow them in that region than it would be to grow palm trees in Minnesota."
Another reason for wanting to restore the native species is that though tropical rain forests occupy less than 7 percent of the earth's surface, they are home to more than half of all plant and animal species.
"I have worked in many tropical rain forests where there are more tree species in 10 hectares - about 25 acres - than in all of the United States and Canada," she said. "That's a remarkable array of potential timbers, medicines and foods to lose."
The total amount of rain forest lost to deforestation may never be known, she said, because more is being cut. Also, small parcels of forest do grow back in some areas.
"Somewhere between 70 percent and 80 percent of Costa Rica's forests have been cut since the 1960s," she said. "There is agreement that the amount of deforested area in the region is probably larger than ever before in human history, and problems are occurring because of this."
One of those problems is deciding exactly which areas to reforest.
"Not only are there often more plant and animal species per small area in a tropical rain forest," Terwilliger said, "but a tropical country as tiny as Costa Rica or Panama will have more kinds of rain forests than there are forest types in all of North America."
To successfully reintroduce a species requires knowing a lot more about how the species grow and survive than is now known.
"Quite a number of people are now studying what it takes for many species to get from a seed to a young sapling," she said. "From this research, introduction of a species whose economic value is already recognized could be accomplished."