With the spread of invasive Phragmites in the Great Lakes basin, scientists and managers in the region are working together to understand the factors that contribute to the spread of this noxious reed and to identify the best strategies to control it. Phragmites has become established over large areas of shoreline, river banks, embayments, and other low-lying areas. Once established, It can be very difficult and expensive to remove. We still have much to learn about the ecology of Phragmites, the effectiveness of different removal efforts such as mowing, burning, and herbicide, and how the most effective treatment may differ based on site conditions and location within the Great Lakes region.
Two current modeling efforts are underway to provide site-specific recommendations of management treatments to a range of stakeholders, from resource management professionals to individual landowners. The two modeling efforts are the Phragmites Adaptive Management Framework’s State-Transition model (or PAMF model), developed by the US Geological Survey, and the Mondrian wetland community-ecosystem model developed by our research group at the University of Michigan. The two models take different approaches and the two teams are collaborating to learn from one another as we all work together with wetland managers to develop strategies for adaptive management of Phragmites invasions. To learn more about the PAMF model, see greatlakesphragmites.net/pamf).
Here we describe our use of Mondrian to develop an online, interactive look-up table tool or quick reference model. The Mondrian modelling team (led by Kenneth Elgersma in this effort, with Jason Martina and Bill Currie) teamed up with Michigan Tech Research Institute, The Nature Conservancy, Michigan Natural Features Inventory, Saginaw Bay CISMA, Michigan DNR, Bay County and USFWS on a project funded by the Michigan Invasive Species Grant Program (MISGP) to develop an interactive tool that would allow managers to get an estimate of the best control techniques based on site conditions.
Mondrian is a complex community-ecosystem model that simulates ecological competition between Phragmites and native plant species, originally designed to help our team to research why Phragmites is such a successful invader. To apply it to the problem of Phragmites removal, working closely with wetland managers, we added to Mondrian the ability to simulate a range of management strategies and their potential effects. While the full Mondrian model can be used by anyone, significant time and training are needed*. To make the results more readily available, members of the Mondrian team compiled a summary of thousands of model simulations for a range of conditions. We compiled the results into an interactive, web-based tool, called a look-up-table. It shows simulated sets of model results for a range of 11 management treatments for Phragmites removal. It allows users to provide site-specific conditions including site water levels, nutrient inflows, surrounding density of Phragmites in nearby wetlands, and length of the growing season (based mainly on north-south location in the basin). The interactive look-up table can be used by land managers, conservation professionals, landowners, or any stakeholders interested in recommendations for the most effective combination of management treatments, according to Mondrian model simulations. This interactive tool is now live and available at this link: Mondrian live look-up table.
*Contact Bill Currie if you are interested in using the full Mondrian model. An executable version, together with default input files and a 70-page user guide are available.