Plumbing trees' plumbing reveals their enginee...( ata are interesting because they show t...)

"The surprise was the extent to which individual trees can make these developmental changes," he said. "There has long been data showing that roots tend to have larger conduits than shoots. But there has not been an analysis like this looking across the gradient of differences within the same plant. And nobody has analyzed roots that go as deep as these," said Jackson. According to Jackson, such insights will improve theoretical models of water transport within trees.

"If you're building a model of water transport and you don't take into account these differences among roots, you could severely underestimate the importance of those deep roots," he said. "Their biomass isn't that great, but they are extremely efficient in transporting water."

In further studies, Jackson and his colleagues are installing instruments on trees to measure their water flow in real time to determine the dynamic effects of the anatomy they have discovered.

"These studies will allow us to ask what proportion of the water in trees comes from different depths and how that proportion changes during drought conditions," said Jackson. "Ultimately, the question behind this work is how much of the water balance of the Edwards Plateau is driven by the vegetation. And for that question, we need more than static physiological measurements. We're already teaming up with hydrologists and geologists in the region to find the answer."

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Contact: Dennis Meredith
dennis.meredith@duke.edu
919- 681-8054
Duke University
19-Aug-2004