Invasive sedge protects dunes better than native grass

 

Photo credit: Science Daily

The Superstorm Sandy storm surge breached the dune line and created a channel that is stabilized by American beachgrass (Ammophila breviligulata) on the left and Asiatic sand sedge (Carex kobomugi) on the right.

Credit: Bianca Charbonneau

Invasive sedge protects dunes better than native grass, study finds

Date:

January 25, 2017

Source:

University of Pennsylvania

Summary:

An invasive dune plant has an advantage over its native counterpart: the invasive is better at preventing erosion of dunes during big storms, report investigators.

The invasive species Carex kobomugi, or Asiatic sand sedge, was first found along the East Coast of the United States at New Jersey’s Island Beach State Park in 1929. The species is aggressive, outcompeting native vegetation and reducing local biodiversity. In many places, land managers have made great efforts to remove it.

But a new study published in the Journal of Applied Ecology and led by University of Pennsylvania doctoral candidate Bianca Charbonneau finds that the invasive plant does have one advantage over its native counterpart, Ammophila breviligulata, or American beach grass: the invasive is better at preventing erosion of dunes during big storms.

With a warming climate battering the coast with more severe storms, the research suggests that, to protect coastal communities, managers may want to give weight to the virtues of the non-native species.

“In order to make an informed management decision, you really need to know all the cards at play and this is an important one,” said Charbonneau, a student in the School of Arts & Sciences’ Biology Department. “If you value the natural composition and habitats afforded by native plant diversity, you should be trying to control this invasive. If your priority is protecting houses on the coast, you might consider letting it lie, or at least letting it lie until there is a plan to replace it so you do not leave a vulnerable unvegetated area in a dune. However, there is a caveat in that we do not know how dunes develop with one species versus another in terms of growth rate and shape.”

Read the full story: Science Daily