Atop a grassy hill a small army advances. As the soldiers close in, the flash of metal blades glints under the scorching sun. At last they come to a stand still. One after another they chop the grass and begin their packs with chopped grass.

The grassy hill is Stanford University’s 2,100 acre Jasper Ridge Biological Preserve and the army is the team of professors and students from Stanford University and the Carnegie Institute in Washington that converge each year at the preserve to take samples of grass for the Jasper Ridge Global Change Experiment (JRGCE).

"It’s not always edge-of-your-seat fun, to say the least, but all the hard work pays off with scientific results that are on the cutting edge of ecological research," co- coordinator postdoctoral researcher Jeff Dukes of the Carnegie Institute in Washington said.

The JRGCE began in 1998 as a revolutionary study of the effects of green house emissions released from cars and factories on grassland environments. Unlike previous projects, which observed only the effects of single factors on the environment, the JRGCE encompasses the combined effects of changes in the levels of carbon dioxide, nitrogen, heat, and precipitation that will result from pollution.

"The thing about this project is that it looks at so many different aspects of change at once. We are able to get a much more comprehensive look than basically anyone else in the world," Dukes said.

Investigations have focused mainly on the effects of the global change factors on biomass, the amount of living matter per unit. Other researchers are taking the experiment to a molecular level, studying the effects on microbes that are involved in the nitrogen cycle as well as genetic changes of these plants. The setup of the experiment includes 32 circular plots, each utilizing different combinations of variable levels of carbon dioxide, precipitation, heat, and nitrogen.

Jasper Ridge was chosen for its warm Mediterranean climate and its annual grasses and shrubs, which undergo a short yearlong life cycle so that results can be easily compared from year to year free from historical defects.

"From my perspective, three things make this project exciting," Chris Field project founder and director of Carnegie Melon Institute’s School of Ecology said. "One is the chance explore responses of real ecosystems to realistic combinations of global change. The second is the chance to follow the ecosystem responses through several generations of the dominant plants and animals. The third is the is the opportunity to address key questions from a range of different disciplines and approaches."

One of the team’s most impressive discoveries came about in late 2002 when scientists noted that increased levels of carbon dioxide when combined with increased nitrogen and precipitation suppressed the positive effects of the nitrogen and water by nearly 40 percent. In the past, single factor experiments had concluded that carbon dioxide increased growth.

"The fact that carbon dioxide suppresses growth really surprised us," Dukes said. "What we’ve found so far suggests that ecosystems are going to slow down sooner due to the rise of carbon dioxide and therefore will result in climate change."

Carbon dioxide is essential for plant growth. So far scientists have not been able determine the reason for the contradictory suppressive behavior of the increased carbon dioxide, nitrogen, and precipitation combination.

Researchers hope to use such findings to create generalizations of how global change factors will affect other ecosystems.

"Some of the research might help understand not only how this system responds but get insight to how other system respond," Dukes said. "The reason the project is important is that on a broader scale it is trying to show how greenhouse emissions will affect ecosystems and how those responses might increase these effects."

To encourage reduction of green house emissions Jasper Ridge scientists do much of their field researches at the emissions free Leslie Shao-Ming Field Station. The building was complete in late 2000 and using only recycled products. It houses classrooms and lab stations. The building runs on solar energy and uses insulation made of newspapers to keep cool in the summer.

"It gets pretty hot up here, but the newspaper keeps the building cool. This building is an example of what we can do to reduce green house emissions," Japer Ridge docent Bob Buell said.
Current funding for the project has come from the US National Science Foundation, and the David and Lucile Packard Foundation, with additional support from Stanford University and the Carnegie Institution in Washington. Past supporters of the project have included the Andrew Mellon Foundation and the Morgan Family Foundation.

The JRGCE is a major step into understanding how the planet will respond to human activities. According to the Jasper Ridge 2002 National Science recently awarded a five-year grant to continue research on the JRGCE and 19 new projects have been initiated at the preserve. Coordinators hope to continue the project until 2013 in order to determine long term effects of global change.

"I think it is good for the community to know that there is some important world class research going on just a few miles away and I think they should recognize that what we found so far suggests that ecosystems may not slow climate change as much as we thought; we really need to think about our actions." Dukes said.