PARENT SESSION
Oral Session #31: Plant Reproductive Ecology, Pollination, and Dispersal. Presiding: J. Karron.
Tuesday, August 7, 2001. 1:00 PM to 5:00 PM. Hall of Ideas L&M.

Reproduction and fire: how prescribed burns enhance pollination of the native prairie plant Echinacea angustifolia.

WAGENIUS, STUART¹, ¹

ABSTRACT- Prescribed burning is a common management practice for prairie remnants because it decreases the abundance of weeds and woody plants while increasing survival and flowering of fire-adapted native plants. Burning is also hypothesized to affect some pollinating insects negatively. In this study, I focus on a self-incompatible prairie plant with generalist insect pollinators, the purple coneflower, Echinacea angustifolia (Asteraceae). For three years I compared the flowering, pollination, and insect visitation of 227 plants growing in a 40 ha prairie preserve with two management units. Alternate units were burned in the spring of the first and third years. I found that a) flowering increased in the burned unit in the burn year compared to the other unit and compared to other years, b) pollination rates were higher in the burned unit than in the non-burn unit in the third year but not significantly different in the first year, and c) the insect visitation rate did not differ between burned and unburned units. These results demonstrate that burning increases flowering and sometimes pollination in this native prairie plant; it does not reduce visitation by common generalist pollinating insects.

KEY WORDS: pollination, conservation, prairie, Echinacea angustifolia