Jon Chase and Tiffany Knight are working hard to save the world — or at least preserve its biodiversity. Chase and Knight head up ecology research at Washington University, each pursuing unique and innovative research programs that underscore a simple premise: Nature’s living organisms depend on one another for survival. This “web of life” concept is the foundation of ecology, the scientific study of the relationships among living organisms and their surroundings. It’s a quantitative science that applies theory and mathematical modeling to critical real-world problems of the environment. Or, as Chase puts it, ecology is “where the ivory tower meets the muddy boots.”
Combining sophisticated techniques with extensive field work, and forging collaborations across Arts & Sciences and the university, the new ecology is tackling some of the toughest issues in our human-modified world, including preserving biodiversity for the benefit of all life, preventing species extinction and restoring lost habitats.
Tipping the scale for biodiversity
Jon Chase, professor of biology and community ecologist, needs space — lots of space. Forget a 24 x 12 lab. His kind of space is measured in acres. Through work that ranges across the Missouri Ozarks, the islands of Hawaii, Canada and Bolivia, Chase has unearthed a fundamental concept: “Most of the biodiversity we see isn’t what’s in one small pond, forest or patch of prairie. It’s about the differences among those patches.” According to Chase, this “beta-diversity,”or the variation in the types of species that live in different places, underlies our global diversity.
Conservation and restoration of degraded ecosystems is informed by betadiversity. “When we want to re-create a community that’s been degraded, we are interested in making it as close as possible to what it was historically,” Chase says. “Usually, we come at it with a Field of Dreams hypothesis: If you build it, they will come back.” A dominant school of world thought in ecology called “niche theory” maintains that environments with a certain mix of habitat, species and resources will produce predictable results.
Understanding the impact of spatial scale is fundamental to understanding the processes that create beta-diversity. Chase illustrates this point with a thought experiment: What happens to plant diversity when you add a lot of nitrogen to an old field? This question has profound implications because nitrogen compounds — byproducts of the burning of fossil fuels and the use of nitrogen fertilizers — are increasingly adding acidity to our soil and water and are helping to deplete ozone in the atmosphere. It’s essential to know the effects of an oversupply. Measuring plant diversity in a 1-meter plot produces results very different from those of a 10-meter area. Researchers may completely miss beta-diversity by focusing only on the smaller scale. That’s why Washington University’s Tyson Research Center offers such a unique opportunity and is crucial to Chase’s ecology research.
Scale also plays a part in Chase’s overall approach to developing general theories. In one research project with a postdoctoral associate and collaborators from the Missouri Botanical Garden, he is comparing tree communities of “tens of species” in the Ozark forests of Tyson and nearby areas with the thousands in the tropical rainforests of Bolivia. He asserts that ecologists are doing pretty well at the largest scales and are capable of delving minutely into the physiology of a particular plant, learning its function in detail. Chase’s work takes place at the complex nexus between these extremes.
Chance plays an important role as well, Chase says. An alternative view to niche theory known as the “neutral theory” states that niche thinking cannot explain all variations and, in fact, may not always help in restoring a denuded community. In his experimental ponds at Tyson, Chase has demonstrated that chance may play a greater role in small areas with few individuals, while areas of larger species density may see more predictable effects from species’ niches and selection. Through mathematical modeling he can forecast when randomness in the ponds will play a larger role. In essence, he’s learning to predict the degree of predictability.
Balancing plant science with human interests
Tiffany Knight is performing work that further establishes the study of ecology as essential to the continuation of life on Earth and that highlights its interdisciplinary nature. Knight, associate professor of biology and plant population ecologist, is also building a crucial new collaboration: the integration of science with social research to address the increasing peril of our planet’s flora at the hand of humanity. “Preserving forests is necessary for all of humanity and for the livelihoods of people in forested communities; we need to work with people and find solutions that sustain both human livelihoods and trees,” she says.
Knight’s work focuses primarily on “biodiversity hotspots” where there are an unusual number of rare plants or there is great biodiversity. Her most recent and most interdisciplinary collaboration came out of a serendipitous decision to sit in on a campus seminar hosted by a faculty member in the George Warren Brown School of Social Work. The topic was poverty and the environment, and the collaboration launched that day has the potential to alter how humans perceive and use natural resources.
In his talk, Gautam Yadama, associate professor of social work, presented a model of a social system in southeastern India, exploring the policies and economics of subsistence living. Villagers in rural areas within the state of Andhra Pradesh, living on the equivalent of less than $1 per day, use the local forests as an important source of sustenance. By cutting trees for shelter, using or selling their limbs for fuel and frequently burning forested areas to create temporary grassland for grazing livestock, the people in this area are taking advantage of the only resource available to them, but contributing to its destruction in the long term.
Figuring predominantly in Yadama’s presentation was the need to understand more about the plant population dynamics in these forests, and Knight saw an opportunity. “It is clear that chopping branches and burning the forest annually will negatively affect its long-term viability,” she says. “What I could contribute from my research is what level of harvesting and fire is sustainable for the trees.” That is, how much can people take before the ecosystem can no longer survive?
Despite the cultural and practical challenges of working in remote India, Knight and Yadama have won funding for a pilot project from the university’s International Center for Advanced Renewable Energy and Sustainability (I-CARES). They made a preliminary trip to the site in 2009, and they plan to return in the summer of 2011. If this proof-of-concept phase is successful, the team hopes to secure additional funding to allow extension of the project and expansion to other areas in Asia. Says Knight, “If we want to solve these problems, we need to find a solution that works for people.”
Human influence on the environment, including the destruction of habitat and removal of plants from their natural environments, has put a startling number of life forms at risk: 20 percent of the Earth’s plant species and nearly 30 percent of amphibians are threatened with extinction in the next few decades, and almost one-fifth of known mammal species face the same danger, according to the International Union for the Conservation of Nature’s “Red List.” Despite grim forecasts, Chase and Knight remain optimistic about the progress made by ecology and its continuing development as a rigorous and far-reaching discipline. Knight characterizes the field’s future as increasingly focused on areas adversely affected by humans “since these are the majority of environments on Earth.” Chase offers an insight into the impulse to investigate our complex world: “There is an inherent value in difference — our species is attracted to it. We like to know that crazy things exist, whether in language, in culture or in species. Diversity has evolved in our psyche and it’s fundamentally human to want to conserve and restore it.”
By Kathy Atnip, A&S Magazine Spring 2011