Divergent responses of cryptic invasive watermilfoil to treatment with auxinic herbicides in a large Michigan lake

Abstract

Parks, Syndell R., "Divergent responses of cryptic invasive watermilfoil to treatment with auxinic herbicides in a large Michigan Lake" (2015). Masters Theses. identification. I am also grateful to the Houghton Lake Improvement Board to allowing Houghton Lake to be used for this study as well as funding the data analysis. Funding for this study was also provided by the Michigan Economic Development Corporation for the additional funding for this study. 4 PrefaceVegetation mapping surveys are an important part of managing invasive aquatic plants.They are used both to characterize the nature and extent of an infestation before designing a management plan and to assess the efficacy of management actions after implementation. This thesis research was conducted on the premise that incorporating genetics into vegetation mapping will improve the design and assessment of invasive aquatic plant control strategies.This idea began with anecdotal reports that invasive watermilfoil had begun to show variation in its response to common herbicide treatments and the discovery, based on genetic studies, that hybrids between Eurasian and northern watermilfoil were present in many treated lakes. Subsequent laboratory studies showed that hybrid watermilfoil were generally less sensitive to the common herbicide 2,4-D. Yet hybrids exhibit so much variation in morphology that they are impossible to visually distinguish from pure Eurasian and northern watermilfoil.Based on these results, we concluded that managed watermilfoil needed to be accurately identified so that hybrids would be detected, if present, and that this could only be done using genetic methods. Currently, however, genetic methods are rarely used when evaluating watermilfoil infestations in managed lakes.Out of the belief that genetic identifications should become an integral part of watermilfoil management, my adviser Dr. Ryan Thum, entrepreneur Linda Chamberlain, and I participated in the National Science Foundation's Innovation Corps program (iCorps). The iCorps program is intended to help researchers and students begin to transfer their research into commercial products through the validation of its value with potential customers. For our 5 team, we needed to determine if managers saw value in using genetic identifications in watermilfoil assessment and treatment, and to determine why they don't use them already.During the program, we interviewed 78 people from 6 states, including state regulators who manage invasive plants and sign off on permits for management, environmental consultants who manage invasive plants on behalf of their customers, and riparian land owners who assess the initial need for management and often hire a consultant to develop and implement the strategy.From those interactions, we determined that most environmental managers did not feel confident that the information provided by genetically distinguishing hybrid from Eurasian watermilfoil would be worth the cost. Many felt that they could accurately identify hybrid watermilfoil visually and di...

Factors Influencing the Distribution of Invasive Hybrid (Myriophyllum Spicatum x M. Sibiricum) Watermilfoil and Parental Taxa in Minnesota

“…[3] and concern has arisen that hybrid watermilfoil may respond differently to management or be more invasive than pure Eurasian [18,19]. Several studies indicate that some hybrid watermilfoil genotypes are less affected by certain commonly-used herbicides than Eurasian, including auxinic herbicides such as triclopyr and 2,4-D (2,4-dichlorophenoxy acetic acid) [18,[20][21][22] as well as fluridone [23][24][25][26]. Parks et al [21] found a greater reduction in Eurasian watermilfoil in comparison to hybrid, following treatment with auxinic herbicides, and similar results were found by Nault et al [20] following treatment with 2,4-D. Fluridone-resistant populations of hybrid watermilfoil have been confirmed in several studies [23,26,27].…”

An Economical Approach to Distinguish Genetically Needles of Limber from Whitebark Pine

“…We accessioned DNA-sequence data and associated metadata, including geographical coordinates and PCR primers, with GenBank (Supplemental Table S1). The protocol for the analysis of restriction endonuclease recognition sites followed Parks et al [24].…”

Lessons from a decade of lake management: effects of herbicides on Eurasian watermilfoil and native plant communities

“…Concern over HWM's invasiveness has been present in APM for over a decade Les 2002, Les andMoody 2007). HWM can be more invasive than its parent M. spicatum: The development of HWM appears to be linked to frequent 2,4-D herbicide application (Larue et al 2013), and 2,4-D has been shown to be less effective in controlling HWM than M. spicatum (Parks et al 2016). The early and frequent chemical treatment of M. spicatum in southern Wisconsin lakes may have facilitated the presence of HWM or selected for the most tolerant milfoil strains.…”