AbstractsBiology & Animal Science

Riparian area invasive plant management along the Niobrara River, targeting yellow flag iris (Iris pseudacorus L.)

by Jordan L Spaak

Institution: Colorado State University
Year: 2016
Posted: 02/05/2017
Record ID: 2079291
Full text PDF: http://hdl.handle.net/10217/176758


Yellow Flag Iris (YFI) (Iris pseudacorus L.) is an invasive exotic species that is causing substantial changes to the ecology of the Niobrara River and the adjacent riparian area habitat. Options for invasive plant management along the Niobrara River, like most riparian wetlands, are quite limited. Currently, herbicides offer the best opportunities for successful YFI management in riparian habitats such as those along the Niobrara River but irrigation diversion and livestock grazing are prevalent which impose further limitations on management options. In this study, we analyzed the efficacy of multiple potential YFI management methods, including; chemical (glyphosate), mechanical (cutting), plant competition, and trampling. A combination of field and greenhouse studies were used. Field studies were conducted at Agate Fossils Beds National Monument, Harrison Nebraska, U.S.A. and greenhouse experiments were completed at Colorado State University, Fort Collins, Colorado, U.S.A. The greenhouse studies were conducted to determine how temperature, light, seed scarification, and trampling, affected germination, seedling growth and survival of YFI. The field studies focused on the effectiveness of glyphosate, cutting, planting native plants, and trampling on YFI. Results from field studies indicate that cutting established plants stimulates YFI growth, spring application of glyphosate resulted in a short-term reduction of YFI abundance, and planting native plants did not reduce YFI abundance. Findings indicate that YFI prefer shaded areas and cooler temperatures for emergence and warmer shaded areas for growth. Seed scarification did not affect emergence. Trampling in the field reduced YFI density by 75% and plant height by 58%. Simulated trampling that targeted the plant crown and 1-2-cm above the crown reduced survival, though trampling that targeted the crown was five times more likely to kill the plant than trampling 1-2-cm above the crown. Advisors/Committee Members: Meiman, Paul J. (advisor), Beck, K. George (committee member), Ocheltree, Troy (committee member).