Flowering Rush (Butomus umbellatus) in Flathead Lake and River: An Integrated Invasive Plant Management Project

Transcription

1 Flowering Rush (Butomus umbellatus) in Flathead Lake and River: An Integrated Invasive Plant Management Project Mara Johnson, Center for Invasive Plant Management; Peter Rice, University of Montana; Virgil Dupuis, Salish Kootenai College; Sue Ball, Confederated Salish & Kootenai Tribes

2 Integrated Project Objectives: Phenology Mapping Spatial model Herbicide and hand digging trials Outreach and Education managers Photo: Alvin Mitchell

3 Flowering rush (Butomus umbellatus) aquatic macrophyte obligate wetland native to Europe & W Asia wetlands, littoral zones of lakes, river edges only species in Butomaceae Photo: Alvin Mitchell

4 Flowering Rush (Butomus umbellatus) Characteristics: umbrella shaped clusters 3 whitish pink petals green stems are triangular in cross section leaf tips may be spirally twisted

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6 FORMS: Fully Submerged Form Emergent Form Terrestrial (Shoreline) Form

7 North American distribution reported by Kartesz as of 1999.

8 Northwest Pacific states counties reporting flowering rush as of 2005 according to Rice.

9 Alberta wild population on the Sturgeon River in central Alberta

10 Potential Impacts: recreation, native plants, wildlife, cultural, etc. Photo: Sue Ball ALSO random control efforts have potential impacts

11 Project Site - Flathead Lake, MT First reported in 1964 in Peaceful Bay, South of Summers

12 Columbia River Basin c0d90ecbf9e57a882571e2006d4abe/$file/colum biabasin_full.jpg

13 March 2007 Photo: Alvin Mitchell

14 Ongoing Projects: 1. Determine reproduction biology, phenology and dispersal 2. Develop a spatial model to predict the biological potential 3. Inventory infestation Photo: Alvin Mitchell

15 Reproduction, Phenology and Dispersal Why Study this Population? Complicated with high variability Confusion in literature Management requires knowledge of growth and reproduction

16 Diploid Eastern N.A. self-compatible prolific flowering high seed production prolific bulblet production (rhizome & inflorescence) may still disperse by vegetative means Triploid Western N.A. self-sterile within clones infrequent flowering low seed production produces low# inflorescence bulblets?? disperses only by rhizome fragmentation

17 Four Forms of Dispersal: 1. seeds 2. vegetative bublets inflorescence 3. vegetative bublets side of rhizomes 4. rhizome fragments

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19 Monitor bublet formation/development/release Inflorescence Bulbils 23% (7/30) umbels had bulbils or arrested flower buds Low # indicative of NA triploids Photo: Alvin Mitchell

20 Seed Production ~120 seeds from the 360 follicles will cold stratify and test for germination literature = triploid low Photos: Sue Ball

21 Flathead Lake = Triploid Photo: Alvin Mitchell Photo: Alvin Mitchell

22 Spatial Model of Flowering Rush Model Output: 1. Areas not likely to be invaded 2. Areas susceptible to future infestation

23 2005 1m CIR imagery W/out Flowering Rush With Flowering Rush

24 2005 1m NAIP imagery Submerged Aquatic Hardstem bulrush Flowering Rush

25 Inventory & Spatial Model Sampling GPS points depth of rush total rush cover Substrate (infested vs non-infested)

26 Other Project Components Photo: Alvin Mitchell

27 Flowering Rush Herbicide Study Study: 3 replications 4 herbicide treatments plus control non-target impacts (other macrophytes) 2 times (early May and late summer) Sites: dense monotype and scattered plots

28 Outreach and Education Methods: Local, regional, national, and international professional and public presentations Professional networking Columbia River manager survey Salish Kootenai College video

29 Mara Johnson, Center for Invasive Plant Management, MSU, Peter Rice, University of Montana Virgil Dupuis, Salish Kootenai College Sue Ball, Confederated Salish & Kootenai Tribes Photo: Alvin Mitchell