PARENT SESSION
Organized Oral Session 3: Plant Pathogens in Nature: Rethinking Vegetation Dynamics
Organized by: CM Malmstrom and A Power
Wednesday, August 6. 8:00 AM to 11:30 AM, SITCC Meeting Room 205.

Accounting for disease in communities: the fourth horseman jockeys for position in the LTER network.

Garrett, Karen^*,1, ¹ Kansas State University, Manhattan, KS, kgarrett@ksu.edu

ABSTRACT- Patterns of fire, precipitation, and grazing have been key factors in the maintenance of tallgrass prairie in the Great Plains of the USA. Konza Prairie Biological Station (KPBS), a Long Term Ecological Research Site in Kansas, has environmental manipulations in place for studying the effects of precipitation changes at the plot level and burning and grazing at the watershed level. I will present results from experiments that a number of collaborators and I have performed to evaluate how these environmental drivers affect plant disease in tallgrass prairie at KPBS. Barley yellow dwarf virus is common in several of the major grass species of KPBS and more abundant in areas without experimentally increased precipitation. Increased precipitation favors abundance of the rust fungus Uropyxis petalostemonis, however, which has a dramatic effect on the reproduction of its host, the legume Dalea candida. Increased precipitation also favors abundance of the rust fungus Puccinia dioicae infecting Solidago canadensis, but proximity of a primary host species was a more important factor in some years. Annual burning greatly reduced infection of the composite Erigeron strigosus by Puccinia dioicae, but had little if any effect on rates of infection of the grass Andropogon gerardii by Puccinia andropogonis.

Key words: tallgrass prairie, disease