Two scientists who drew important links between local and global ecosystems --- a prescient explorer of nitrogen's wide-ranging impacts, and a central figure in the rise of international ecology -- will share the 2008 Tyler Prize for Environmental Achievement.
The award, consisting of a $200,000 cash prize and gold medals, will go to James Galloway, professor of environmental sciences at the University of Virginia, and Harold Mooney, professor of environmental biology at Stanford University.
On Thursday, April 10, at 2 p.m., Galloway and Mooney will deliver public lectures at the Davidson Conference Center of the University of Southern California, which administers the prize.
On Friday, April 11, at 7 p.m., the Tyler Prize executive committee and the international environmental community will honor the recipients at a banquet and ceremony at the Four Seasons Hotel in Beverly Hills.
When the acid rain crisis of the 1970s began easing due to better control of nitrogen and sulfur emissions, many ecologists moved to other research areas. Galloway knew better.
"He was one of the few in the U.S. who realized that critical issues remained unresolved, especially in the area of nitrogen deposition," wrote John Aber of the University of New Hampshire, one of several leading environmental scientists who supported Galloway's nomination.
"In this arena, Jim has truly become the national and international leader," Aber added.
Galloway and his colleagues wrote the key papers presenting the "nitrogen cascade," a flow chart showing the pervasive and persistent effects of reactive nitrogen on Earth's environment.
Nitrogen in its inert form is harmless and abundant in the atmosphere. But in recent decades, massive amounts of reactive nitrogen compounds, such as nitrous oxide, have been entering the environment. Most have come from the use of nitrogen-based fertilizer.
Galloway used the cascade image to describe the sequential impacts of reactive nitrogen. A nitrogen atom that starts out as part of a smog-forming compound may then be deposited in lakes and forests as nitric acid.
Carried out to the coast, the same nitrogen atom may contribute to red tides and dead zones. Finally, the nitrogen may be put back into the atmosphere as part of the greenhouse gas nitrous oxide.
"We're accumulating reactive nitrogen in the environment, and this is as much of a legacy as putting carbon dioxide in the atmosphere," Galloway said.
"The public doesn't know about nitrogen, but in many ways it's as big an issue as carbon, and due to the interactions of nitrogen and carbon, makes the challenge of providing food and energy to the world's peoples without harming the global environment a tremendous challenge."
Galloway and others have suggested possible approaches to minimizing nitrogen use, such as optimizing its uptake by plants and animals, recovering and reusing nitrogen from manure and sewage, and decreasing nitrogen-intensive livestock farming.
When Mooney began his career in environmental science, scientific efforts were focused on local interactions of people, pollutants and species.
"All the energy was focused on small phenomena. Ecologists had to develop tools to scale up their vision of the world," Mooney said.
He became a central figure in that effort, starting or helping to start many of the major global ecology programs of the last 40 years, such as the Global Invasive Species Program, a global program on the Ecosystem Functioning of Biodiversity, the Global Biodiversity Assessment, the Millennium Ecosystem Assessment and others.
"He has been the single-most important ecologist in the last decade in advancing the relevance of our subject to global problems," wrote Simon Levin of Princeton University, in support of Mooney's nomination.
Thomas Lovejoy, president of the H. John Heinz III Center for Science, Economics and the Environment, wrote: "The profession has become that of 'planet doctors.' Hal Mooney's career exemplifies that in stellar fashion."
Jane Lubchenco of Oregon State University wrote: "Others are better known, but he has achieved more because he has empowered, inspired and enabled the vast international scientific community to be relevant. Mooney has done more for the well-being of the planet than any other scientist alive."
A noted researcher in his own right, Mooney provided key evidence for the theory of convergent evolution, which holds that different species in widely separated ecosystems, but with similar climates, all tend to evolve toward similar endpoints.
Mooney's studies of areas with Mediterranean climates showed that plants and animals in similar ecosystems develop similar ways of adapting to their environments.
Mooney also helped develop an economic approach to plant evolution, in which plants are viewed as individuals striving to make the most of their capital (in the plants' case, carbon and energy derived from photosynthesis).
He showed that just as with people, capital allocation in plants involves trade-offs between competing demands, such as growing roots or adding leaves.
For both Mooney and Galloway, inclusion in the group of past Tyler Prize winners made the honor particularly significant.
"Some of the people I've worked with in the past, and certainly some of the people whose work I've used, have received it. It's a heady group to be a member of," Galloway said.
"I'm excited and humbled at the same time because I know most of the past winners and admire them greatly," Mooney said.
ABOUT THE TYLER PRIZE
The Tyler Prize for Environmental Achievement is one of the premier awards for environmental science, energy and environmental health.
It was established by the late John and Alice Tyler in 1973 and is awarded annually to individuals associated with world-class environmental accomplishments.
For more information on the Tyler Prize and its recipients, visit www.usc.edu/dept/LAS/tylerprize.