'Biodiversitree' Project Studies Health Of Tree Species

John Parker knows a lot about biodiversity — he's been studying it for about 20 years, but never like this.

Parker is a senior scientist at the Smithsonian Environmental Research Center, and he's standing at the end of one of the six fields that make up the BiodiversiTree experiment, a project that will monitor the ups and downs of thousands of trees over the course of an entire century.

"This is the biggest thing we've ever done so far," he says. "I think about five people, including 100 volunteers to six weeks in the spring working almost every single day."

Parker says the idea for BiodiversiTree is connected to the longstanding concern about the effects of agricultural runoff polluting the Bay.

"One of the ways in which we've tried to restore the Chesapeake Bay as a whole here in Maryland, is to plant more forest in the critical zone bordering the Chesapeake Bay and important tributaries. So what we decided to do is not just to restore forest next to the Chesapeake Bay, but we decided to make an experiment out of it," Parker explains.

The experiment involves 32 acres of land that's been planted only with corn for the past 35 years. The corn is now gone, and in its place, Parker and his volunteers planted one tree every 8 feet — that's 18,000 seedlings, with more planned in years to come.

Diversity is the point, and there are 16 different species in the ground here, but exactly where they're planted is also important. Parker and his colleagues want to find out if and exactly how biodiversity helps forests survive.

"The best way to test that is to set up artificial communities that have either low diversity, a single species, so these tall trees over here are all sycamores, but over to my right we have a plot that's got actually four different species in it," he says.

Parker says BiodiversiTree is the largest such experiment in North America. While at this early stage they don't have much data, the potential for studying everything from nutrient retention in soil, to storm water runoff from these fields into the Bay, is almost endless as the project moves forward.

The data will tell an important story, but Parker says he's most looking forward to simply walking through these fields and looking at these forest communities as they reach maturity in 10 or 15 years.

"As you're walking through just a Sycamore monoculture — are there more birds? Fewer birds? Is the soil different? Does it just have a different feel than a polyculture?" Parker says. "Then we can go through and quantify those differences later. And from a scientific perspective, that's really the focus of this experiment: does a diverse system function any differently than a less diverse system?"

The scientists — make that a few generations of scientists — should have at least a century to answer that question.

[Music: "Biodiversity" by Chris McKhool from Earth, Seas, and Air]