Clues to determining how these factors contribute to global climate change lie in scientists investigating how plant and animal activity in the rainforest treetops, known as the canopy, may potentially influence soil processes decomposition, respiration and nutrient availability on the rainforest floor.

Working at the Smithsonian Tropical Research Institute's facilities on Panama's Barro Colorado Island, scientists are linking the two rainforest layers in one overall tropical examination.

"The rainforest canopy is the hotspot for animals and plants. It's the hub of activity that keeps the world going," said Meg Lowman, an expedition researcher and professor of environmental studies at the New College of Florida in Sarasota. "No one measured the canopy until 20 years ago, and now that there are long-term sampling data of both the canopy and floor, we need to look at the bigger picture: how the rainforest ecosystem is connected as a whole."

Expedition scientists are connecting the two rainforest layers by examining the effects that canopy materials such as insect feces (frass), green leaves, dead insects and rainwater have on the rainforest floor, when they fall from the canopy.

"We're predicting that an increase in falling canopy materials, will raise the amount of carbon, nitrogen and phosphorus in the forest floor soil," said Lowman. "That will in turn, boost the rate of leaf litter decomposition, which escalates plant growth rates. This is a vital part of sustaining a healthy tropical environment."

"Portions of the half-eaten leaves and insect droppings eventually fall to the rainforest floor," Lowman said. "That is where a lot of the magi
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Contact: Jennifer Walsh
pr@jason.org
972-604-1751
Smithsonian Tropical Research Institute
5-Feb-2004