Bogged Down in Phragmites: Assessing Risk in the Great Lakes Basin

Category: Monitoring Environmental Health and Disturbances
Project Team: Great Lakes Ecological Forecasting
Team Location: NASA Goddard Space Flight Center – Greenbelt, Maryland

Utilizing Earth observations and habitat models to generate a suitability risk map for Phragmites australis in the coastal Great Lakes and St. Lawrence River Basin. Image Credit: Great Lakes Ecological Forecasting Team

Utilizing Earth observations and habitat models to generate a suitability risk map for Phragmites australis in the coastal Great Lakes and St. Lawrence River Basin. Image Credit: Great Lakes Ecological Forecasting Team

Carl Issac Kinton
Peter Jacobs
Sean McCartney

Dr. Laura Bourgeau-Chavez (Michigan Tech Research Institute)
Dr. Kurt Kowalski (USGS Great Lakes Science Center)

Past/Other Contributors:
Sean McCartney (Center Lead)


Phragmites australis is an invasive species that threatens wetland habitats in the Great Lakes and St. Lawrence River basin. Governments in both Canada and the United States recognize that Phragmites detection is a first line of defense in limiting the spread of this species. Left untreated, Phragmites australis outcompetes native regional wetland species, resulting in monotypic stands of invasive Phragmites. As a result, habitat for native fish and wildlife becomes unsuitable, fire risk grows, and elevation of the landscape increases due to an expansion of below-ground biomass, depriving wetlands of nutrients needed by native flora and fauna. Project goals included identifying relevant drivers of the extent of Phragmites and forecasting near-term Phragmites extent throughout the Great Lakes basin. Research from this project will help the Great Lakes and St. Lawrence Cities Initiative in its goal to distribute Phragmites information to local policymakers in both the U.S. and Canada. Earth observations (EO) utilized included Shuttle Radar Topography Mission (SRTM), Tropical Rainfall Measuring Mission (TRMM), and Global Precipitation Measurement (GPM). Ancillary datasets known to correlate with Phragmites also were used as model variables. Land use/land cover (LULC) maps were created using TerrSet Land Change Modeler. MaxEnt habitat suitability modeling used environmental variables and LULC classifications to forecast Phragmites habitat suitability extent through the year 2020. Forecasting results will help local governments enact policies to plan for and mitigate the spread of Phragmites australis. Challenges and limitations included finding an alternative to mapping Phragmites using radar data, and acquiring current LULC maps of the study area.

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Emily Gotschalk 14-04-2016, 16:52

Have you considered adding any hydrologic data to this project? Tidal inundation is another factor that can impact Phragmites success.

Sean McCartney 20-04-2016, 15:06

Hi Emily,

Terrific question. We did consider adding hydrologic datasets into our models but ran out of time. This is definitely something to explore going forward and we included this in our suggestions and future work with our project partners. Thanks!

Daryl Ann Winstead (Lake Victoria Water Resources II) 13-04-2016, 21:00

Great video! Very informative! How were the non-native Phragmites introduced to the Great Lakes?

Issac Kinton 14-04-2016, 13:56

Hey Daryl,

First off you guys did a great project on water hyacinth. There are a lot of parallels between our projects!

To answer your question, some background information is needed. First off, there are many species and subspecies of Phragmites. The invasive species, Phragmites australis subsp. australis, is the main problem to to its aggressive expansion. Phragmites australis subsp. americanus on the other hand is a native variant that is much less vigorous in growth. These two sub species are very similar with the main difference being their expansion rates.

With that in mind, Phragmites was introduced way back when Europe colonized North America. Its rapid growth in recent decades stem from a large increase in development along vulnerable areas.

Daryl Ann Winstead (Lake Victoria Water Resources II) 15-04-2016, 16:02

Hi Issac!

Thank you for answering my question! How was the team able to tell these species of Phragmites apart? Did the team have access to in situ data?

Sean McCartney 20-04-2016, 15:12

Hi Daryl Ann,

We did indeed have access to in situ data from one of our project partners, Michigan Tech Research Institute (MTRI). They collected field data from 2010-2011 ( and we added more in situ data acquired from the Global Biodiversity Information Facility ( This is an excellent source for presence data for A LOT of flora and fauna, if you are doing similar projects in the future.

Jessica Sutton 13-04-2016, 15:46

Very interesting VPS! Based on your knowledge of Phragmites, do you think the most important predictor variables would change or stay the same in a different study area? Nice work!

Sean McCartney 20-04-2016, 15:20

Hi Jessica,

Very good question. I do think the predictor variables would change depending on if the study area were more urban or wild, and if the climate were more temperate. The other factor would be where the presence locations of known Phragmites stands were collected in the field. It would be interesting to apply the methodology used to say, the Chesapeake Bay, and see how much the predictor variables change with location. Thanks for your feedback and compliments!

Michael Riedman 12-04-2016, 07:57

Great video! Very well put together! Really shows the potential invasive species have to disrupt the ecosystem. It would be interesting to see a map or visual of other areas in the United States plagued with phragmites.

Sean McCartney 20-04-2016, 15:04

Hi Michael,

Thanks for your feedback! There have been some web based platforms to map Phragmites in the Chesapeake Bay watershed:
The US Fish and Wildlife Service is also devoting a lot resources to combating the common reed, and that might be a good source for maps in other regions of the country. Hope this helps!

Sara Lubkin 09-04-2016, 18:35

A very interesting project, especially since invasive Phragmites growth is becoming all along the U.S coast. I think it’s great that you were able to forecast future spread of P. australis along the Great Lakes and St. Lawrence River based on variables that favor growth. I know that fighting Phragmites is time-consuming and very expensive, so your data will really help communities use their resources wisely.
I also noticed that you used in-situ data to identify the current extent of P. australis. Are you aware of NASA Earth Observations that can be used for historical studies of the spread of the reed?

Sean McCartney 12-04-2016, 15:44

Hi Sara,

You could not be more correct in typing fighting Phragmites is time-consuming and very expensive!
Great question. Most EO pertaining to our project date from 2000 – present. For land classifications, Landsat 5 – 8 are great sources of EO for classifying and measuring proximity to different land cover types used as driver variables of change. We used MERRA data in place of MODIS data since it has a longer temporal component. Hope this helps and look forward to discussing this in person with you over the summer!

Leigh Sinclair 08-04-2016, 15:25

Great job on this! What’s the accuracy on the Habitat Risk Maps?

Sean McCartney 12-04-2016, 15:52

Thanks Leigh! Great job on the AL Eco-Forecasting project! You all did a fantastic job modeling the southern pine beetle.
To answer your question, accuracy on all model runs was >= 0.85 AUC.


Leigh Sinclair 13-04-2016, 11:33

That’s awesome! Thanks!

Lori Mandable 07-04-2016, 17:20

Fantastic video that provides the viewer with information regarding the invasive species Phragmites around the Great Lakes region. The video conveys the extent of Phragmites as well as the variables used in modeling future growth of the species, showing how stakeholder data can be integrated with NASA Earth observations to provide critical information to regional officials to control the spread of Phragmites.

Sean McCartney 12-04-2016, 15:55

Thanks for the comment Lori! Glad you were able to understand our project through watching the video, and take away how stakeholder data can be integrated with NASA Earth observations to provide critical information to regional officials in the Great Lakes Basin. Controlling and mitigating the spread of Phragmites is a big concern for the stakeholders in the region. Thanks!



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