Nearly 150 volunteers collaborated to map four non-native invasive plant species in eight southeastern Wisconsin counties last summer, and the data keeps pouring in.
Eight County Leaders were selected to recruit mapping teams of two for each township in the SEWISC region. Team members received training, data sheets and maps which were provided by County GIS Departments and the University of Wisconsin-Milwaukee American Geographic Society Library. The volunteers collectively surveyed more than 11,000 miles of roadways, devoting over 1,200 hours to the project.
SEWISC's 2011 Invasive Plant Roadside Survey covered all roads with lane markings within Sheboygan, Washington, Ozaukee, Waukesha, Milwaukee, Walworth, Racine and Kenosha Counties. Township Mapping Teams also performed surveys focusing on areas in or near primary and secondary environmental corridors and isolated natural resource areas.
Giant reed grass (Phragmites australis) was mapped in 799 locations, common and cut-leaved teasel (Dipsacus sylvestris and D. laciniatus) were mapped in 1,125 locations and Japanese knotweed (Polygonum cuspidatum) was mapped in 133 locations.
These species were selected because they are, 1) common, but still in early stages of infestation in our region, 2) not uniformly spread throughout the region, 3) spreading along roadways, and 4) easy to recognize throughout the year. Although these species have limited distribution in southeastern Wisconsin, each has the potential to spread rapidly along roadsides and rights-of-way. With training, these species were safely identified and mapped by teams of two or more travelling on foot, bicycle or by vehicle.
A very brief summary of the survey instructions is as follows:
• Participants completed survey protocol training and submitted a liability release.
• Survey teams of at least two were required for each township. One team member was charged with safely driving the car while the passenger navigated and recorded populations on the map and data form.
• All populations visible from the road were recorded. A special effort to survey environmental corridors was made.
• Populations were recorded with a dot on the map and labeled with a number. Species and population size codes corresponding to that number were recorded on the data sheet. Populations which were located within the right-of-way were noted.
• All roads surveyed were marked with a highlighter on the map. Maps and data sheets were submitted to SEWISC and the survey data was entered into a digital geodatabase.
The majority of the mapped populations were relatively small, and teasel populations were, on average, smaller than either Japanese knotweed or Phragmites.
It was clear from the mapped populations of the species that they were not uniformly distributed throughout the eight-county region.
Japanese knotweed was the least common of the species, but had a concentration of populations in north-central Sheboygan County in the northern part of our region.