research results show invasion
Hybrid cattail found to be swarming locally
By Heather Augustyn
Northwest Indiana Times
Published February 2, 2006
PORTER | The second day of February is traditionally
reserved for the groundhog.
But the groundhog's fellow wildlife friends may be celebrating
a different holiday in honor of their habitat -- World
Wetlands Day, which marks the date the Convention on Wetlands
was signed in 1971.
First celebrated in 1997, World Wetlands Day makes aware
the issues of wetland conservation and preservation around
the globe. And here at home, much is being done to steward
our own resources in the acres of unique landscape.
Joy Marburger, research coordinator at the Indiana Dunes
National Lakeshore, and her colleagues have just completed
preliminary research at Cowles Bog, one of the more well-known
wetlands in Porter County.
Research suggests that an invasive species of cattail
has spread and created a hybrid that dominates the habitat.
"This two-year project is aimed squarely at uncovering
the role of hybridization in the spread of cattails in
three Great Lakes national parks," said Marburger,
who used material from more than 700 cattails collected
in the area and other wetlands.
"The overall situation has apparently progressed
to the level of what plant biologists commonly refer to
as a 'hybrid swarm' throughout much of the Great Lakes
region," Marburger said.
She said that the hybrid is a combination of the invasive
narrowleaf cattail, which likely came via ship from Europe
in the 1800s and spread slowly to the Midwest, and the
native broadleaf cattail. The hybrid was first discovered
in the 1960s, but its prominence has not been studied
"The message from this research is that hybridization
may provide an important piece of the puzzle in the cause
of the invasive spread of cattails across the Great Lakes
national parks," Marburger said. "Nutrient runoff
from urban and agricultural lands, as well as flood control,
may also be contributing factors in the spread of hybrid
Researchers will now consider next steps.
Dan Mason, botanist at the Indiana Dunes National Park,
and his team are actively removing the hybrid cattail
and replanting native wetland plant species.
Volunteer help has been an integral part of this restoration.
"More ecological testing will be needed to piece
it all together, but ultimately resource managers will
be provided with a clearer understanding of what they
must do to preserve the genetic integrity of the pure
native cattail and to control the unwanted spread of hybrid
cattails in an effort to maintain and enhance wetland
biodiversity throughout the Great Lakes region,"