LAWRENCE — Grasslands around the world vary tremendously in their biodiversity — the wealth of species they harbor. Diverse grasslands are not only more productive but also more resilient to unpredictable events, such as drought or flooding. A new study, funded by the National Science Foundation and led by University of Kansas scientists, focuses on what may be a key factor in maintaining biodiversity: the microscopic organisms in the soil, particularly plant pathogens.
“Scientists still don’t agree on the natural forces that create and maintain rich grassland diversity,” said Jim Bever, principal investigator. “But recent research suggests these tiny organisms are crucial. Our project tests whether plant disease determines natural patterns of plant diversity and regulates biodiversity.”
Bever is a KU professor of ecology & evolutionary biology and a senior scientist at the Kansas Biological Survey, a KU research center. He said it was essential to understand the processes that govern both the patterns and the benefits of plant diversity: “This knowledge could generate new directions for sustainable management of rangelands. It also could improve the yield and resilience of degraded agricultural and native ecosystems.”
The $1.7 million study is one of seven funded this year through the National Science Foundation’s Dimensions of Biodiversity program. This special research initiative integrates multiple areas of study, in contrast to traditional biodiversity studies that focus on one taxonomic group or ecosystem.
The researchers expect high levels of precipitation to facilitate pathogen spread in grasslands, for two reasons. First, life cycles of many pathogens depend on moisture, and second, pathogen spread increases with plant density, which is associated with greater moisture levels.
Pathogens can build up and limit plant productivity. Because many pathogens are specialized on their hosts, they are predicted to spread most rapidly in grasslands with large populations of the same plant species and low genetic diversity. Pathogen build-up on monocultures (i.e., agriculture) or low-diversity grasslands creates opportunities for invasion by other plant species, thereby increasing plant diversity.
Through a coordinated set of field observations, field manipulations and greenhouse experiments taking place in the central U.S. and China, the study will test three categories of patterns:
- plant and pathogen diversity;
- plant resistance due to genetic diversity; and
- ecological and evolutionary feedback across parallel rainfall gradients.
The researchers will use rainfall manipulations in experimental plant communities to test the environmental dependence of plant species coexistence, the productivity benefits of plant diversity and the role of pathogens as drivers of these processes.
Data from these experiments will be integrated with mathematical models to generate predictions of patterns and benefits of plant biodiversity — as well as predictions of grassland vulnerability to environmental disturbance.
The project also will support training of new scientists through collaborative research and summer programs focused on regional biodiversity across Illinois, Missouri and Kansas.
Co-principal investigators on the project:
- Helen Alexander, professor of ecology & evolutionary biology;
- Bryan Foster, professor of ecology & evolutionary biology and senior scientist at the Kansas Biological Survey;
- Peggy Schultz, of the Bever/Schultz Lab, lecturer in the Environmental Studies Program and research specialist at the Kansas Biological Survey; and
- Ben Sikes, assistant professor of ecology & evolutionary biology and assistant scientist at the Kansas Biological Survey.
Projects chosen for the NSF Dimensions in Biodiversity awards are aimed at filling gaps in biodiversity knowledge. They also have the potential to lead to significant progress in agriculture, fuel, manufacturing and health.
The Kansas Biological Survey houses diverse environmental and graphic information systems research programs and also manages the 3,800-acre KU Field Station. The survey was established at KU in 1911.
The Department of Ecology & Evolutionary Biology is part of the College of Liberal Arts & Sciences. The College is the heart of KU, with more than 50 departments, programs and centers, as well as the School of the Arts, School of Literatures, Languages & Cultures, and School of Public Affairs & Administration.
Photo: Sheena Parsons, research technician in the Bever/Schultz Laboratory, monitors prairie species in the state-of-the-art greenhouse on West Campus where part of the work for the study takes place. Credit: Kirsten Bosnak