September 29, 2006

If A Tree Is Not In The Forest, Can You Hear It Fall?

What tree doesn't like a forest? The Live Oak, which apparently is the introvert of the tree family. A study of the live oak by University of Florida researchers reveals that live oaks are under pressure in Florida (an no doubt elsewhere) from the encroachment of other trees:

It is an irony of nature that the successes of reforestation and urban forestry threaten live oaks, which in the past maintained the elbow room they needed from logging, cattle grazing and frequent fires, said Putz, whose work is published in the June issue of Forest Ecology and Management. “We are confusing our natural savanna heritage with forested landscapes and the tragedy is that the forest is killing live oaks,” he said. “If we allow other trees to grow up too close to the live oak, the live oak will die. Our research clearly establishes this fate in both rural and suburban landscapes.”

...

Based on these findings, Putz said he believes more than half of the live oaks in the city of Gainesville alone are in danger of being destroyed by encroaching trees, a process that can take anywhere from 10 to 30 years and is most rapid in the suburbs where lawns are fertilized.

The problem is widespread because suburban sprawl and forest expansion are threatening savannas and open-canopied woodlands in many parts of the world, Putz said.

“The trees of these savannas, from the oaks of California and Europe to the acacias of Africa and the legumes of tropical America, are all likely to suffer when forest trees encroach on their crowns,” he said. “In the U.S. alone, savanna is the natural vegetation all across the coastal plain from Virginia to Texas.”

Saving live oaks sometimes means having to kill other trees, which can be expensive, but preserving a single live oak can add as much as $30,000 to the value of a house, Putz said. Furthermore, having a live oak nearby is good protection against hurricane damage.


I have to admit it's counter-intuitive for me to consider the growth of forest can come at the expense of a particular tree species, or to contemplate killing one set of trees to save another.

Posted by Kevin Murphy at September 29, 2006 12:51 PM | Science