A big bet revolutionizes global forest science

"Visitors to the Smithsonian Tropical Research Institute often ask our researchers if we are seeing the effects of global change," said Ira Rubinoff, STRI’s director emeritus. "The answer is ’yes, we can,’ but only because we began to monitor forest biodiversity a long time ago."

In 1980, Stephen Hubbell and Robin Foster approached Rubinoff with a simple question and a bold idea. They wanted to shed light on a mystery that had dogged tropical biologists for decades: Why are there so many species of trees in a tropical forest? To test the question, they argued, they would need to set up a large−scale, long−term project.

There was just one catch: they wanted to keep all other researchers off of their outdoor laboratory. Since their study concerned the dynamics of the plot, they needed to assure human traffic wouldn’t trample seedlings. Fresh growth is the most sensitive to change in a forest.

Rubinoff reluctantly agreed to let them essentially cordon off 50 hectares of old growth forest on Panama’s Barro Colorado Island for their experiment. There, Hubbell and Foster identified, mapped and measured every tree with a trunk thicker than a thumb. The first painstaking census counted a quarter−million trees that represented more than 300 species.

And then they left the forest alone for half a decade.

When they repeated the census five years later, they found that the centuries−old forest had changed relatively quickly, in terms of both species distribution and composition. "There was this idea that forest communities were relatively stable," recalls Rubinoff. "It turned out that wasn’t the case."


Scientists around the world took note of the findings on the 50−hectare plot. Within a few years, a global network of forest plots was established based on Hubbell and Foster’s research protocols.

Now called ForestGEO, the Smithsonian−coordinated network allows researchers from around the world to address questions ranging from the basics of biodiversity to the complexities of the carbon cycle. In just one recent example, the BCI plot’s three−plus decades of data was essential to the Carnegie Airborne Observatory’s collaboration with STRI to create the highest resolution carbon map of a nation to date using Light Ranging and Detection technology.

"I had serious doubts about permanently setting aside such a large area for a single experiment, but once the results came in I knew we had done the right thing," said Rubinoff, adding that he did not expect a basic biology project to flourish into a global reference for forest study.

Rubinoff’s big gamble had paid off in ways he had never imagined.

"Theirs was strictly a biological question," says Rubinoff. "We didn’t think about it at the beginning − that the basic information was going to have so many applicable uses."

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