Belowground Meristem Populations as Regulators of Grassland Dynamics

Kansas State University, Manhattan KS

Investigators

Abstract

Studies of plant populations are critical for linking organism traits to ecosystem function, and for understanding ecosystem response to climate change and patterns of biodiversity. In perennial grasslands and other plant communities, the belowground population of meristems (the bud bank) plays a fundamental role in local plant population persistence and dynamics, and may also determine community diversity, stability and invasibility. At the ecosystem level, bud banks and meristem limitation can strongly influence patterns of primary productivity and carbon dynamics and responses to environmental change. This proposal tests hypotheses about the community and ecosystem consequences of belowground meristems in grasslands. The specific objectives are to test the hypotheses that 1) bud bank densities vary across precipitation gradients, 2) meristem limitation constrains productivity responses in arid to semi-arid grasslands, 3) bud banks and meristem density regulate the invasibility of grassland plant communities to exotics, and 4) fire, grazing, and water limitation regulate the patterns of bud bank populations in grasslands. The densities, dynamics, composition and viability of belowground meristem populations, aboveground populations, and patterns of aboveground net primary productivity, will be measured over a 3-yr period across the Great Plains in 7 sites that vary in precipitation and productivity. The proposed cross-site activities will include 3 LTER sites and enhance collaboration among grassland-based research scientists within the central U.S. region. This research will provide a better predictive understanding of how grassland ecosystems respond to global climate change, invasion of exotic species, changing land management (fire and grazing regimes).