Fire and Canopy Removal Effects on Demography and Reproduction in Turkeybeard (Xerophyllum asphodeloides), a Fire-Dependent Temperate Forest Herb

Abstract

We examined the effects of fire and canopy disturbance on turkeybeard (Xerophyllum asphodeloides [L.] Nutt.), a rare temperate forest herb. We used long-term data and a fire and canopy alteration experiment with controls to address our hypothesis that turkeybeard is fire-adapted. Analyses of a primary study population demonstrated that turkeybeard is a long-lived, infrequently flowering perennial with high survival and rapid postfire resprouting ability. Experimental responses showed that population-level flowering and inflorescence production increased 60–280% across treatments compared to controls in two posttreatment seasons. Seed production/inflorescence was significantly higher in treated plants. Fire and canopy removal treatments had a positive and additive effect on seed set compared to controls. Additional population surveys and pollination experiments showed that turkeybeard exhibited low flowering levels in undisturbed forest and required outcrossing for good seed set. Burning released plants from these limiting factors by inducing mass-flowering and altering the forest habitat to attract insect pollinators. Our research demonstrates that turkeybeard is one of the few known definitively fire-adapted montane forest understory herbs in the eastern United States, such that fire management including prescribed burning is recommended for its conservation and management. It also adds new impetus for studying fire’s ecological role in these lands.