Altered rainfall due to climate change: Modeling the ecological effects on grasslands

TitleAltered rainfall due to climate change: Modeling the ecological effects on grasslands
Publication TypeThesis
Year of Publication2008
AuthorsHoover, DL
DegreeMS Thesis
Number of Pages1 -63
UniversityUniversity of Connecticut
Thesis TypeM.S. Thesis
Accession NumberKNZ001224
KeywordsClimate variability, Ecosystems, Impacts of global change, Land/atmosphere interactions, structure and dynamics

The acceleration of the hydrological cycle due to global climate change is predicted to cause more extreme precipitation, characterized by fewer but more intense storms. Such altered rainfall patterns will have significant impacts on water limited ecosystems such as grasslands. This project used a land surface model, the Community Land Model 3.0 coupled with a dynamic vegetation model, to examine how changing the size and frequency of rain events impacts plants, surface hydrology and surface energy budgets in the tallgrass prairie ecosystem. We applied a similar rainfall scheme as the Rainfall Manipulation Plots at Konza Prairie Biological Station in Kansas, which consisted of an altered rainfall treatment, with fewer but more intense events, and an ambient treatment, which replicated the natural pattern of rain. Both the model and field experiments show a reduction in grass productivity from the ambient to the altered treatment and a negative correlation between soil moisture variability and productivity. In addition, based on the modeling results, the altered rainfall treatment increases runoff, decreases evapotranspiration, and increases sensible heat flux at the expense of latent heat flux.