Jesse Nippert, professor in the Division of Biology at Kansas State University, received three new awards from the National Science Foundation to study the dynamics and impacts of global change on grassland ecosystems. Two projects will use the experimental infrastructure of the Konza Prairie Biological Station located 10 miles south of Manhattan, and the other is in the Limpopo Province of South Africa.

A three-year $147,000 award, funded by NSF-Hydrological Sciences, will support Nippert’s role in an interdisciplinary project with Pam Sullivan, Oregon State University; and Li Li, Penn State University. This research will investigate the consequences of woody plants replacing grasses in tallgrass prairie. Deeper roots associated with woody encroachment are likely to enhance transport of water and carbon to greater depths and increase potential subsurface weathering. This research incorporates hydrologic sciences, ecology and geochemistry to better understand how water moves within the landscape, how roots modify subsurface flow paths, and how the replacement of grasses with woody plants may accelerate weathering in the karst landscapes of the Flint Hills.

Nippert also was awarded a three-year $299,000 grant funded by the NSF-Macrosystems Biology and NEON-Enabled Science program to work with Chris Still and Daniel Griffith from Oregon State University; Brent Helliker, University of Pennsylvania; William Riley, Lawrence Berkeley National Labs; and Stephanie Pau, Florida State University.

This project will add new knowledge on anatomical and physiological grass species traits to enhance fundamental understanding of grass-dominated ecosystems, with many applications in agriculture and natural resource management.

The research team will develop an integrative framework that organizes grass vegetation types around phylogeny-driven functional diversity.

The research will be done along environmental gradients in North America at select National Ecological Observatory Network and Long-term Ecological Research sites, including Konza Prairie. The results will increase the accuracy of site-, regional-, and Earth-System-Model-scale predictions, and improve forecasting of how grassy biomes will respond to increasing CO2, climate change and disturbance.

Nippert also received a three-year $241,000 award from the Population and Community Ecology Cluster within the NSF-Division of Environmental Biology.

He and his collaborator, Ricardo Holdo at the University of Georgia, will investigate how changes in rainfall may alter the coexistence of grasses and trees in South African savannas. This research combines experimental, observational and modeling approaches to identify mechanisms that facilitate shifts in the tree-grass balance following alterations in precipitation.

Similar to grasslands in the U.S. Great Plains, many savannas are threatened by the phenomenon of woody encroachment, which leads to the loss of the grass layer. Given these threats, further study of the factors that allow savannas to persist through time is of critical importance.

Results from this project will also apply to the restoration and conservation of savannas in North America and elsewhere.