Invasive Oriental Bittersweet A Threat to Trees in Connecticut River Valley

Early research in an ongoing study on the impact of the invasive vine “Oriental Bittersweet” shows that in the Connecticut River Valley, the  vine  is now the second leading cause of mortality of floodplain trees in Massachusetts and Connecticut, and it’s spreading fast. 

The Nature Conservancy’s Christian Marx says the invasive oriental bittersweet kills a trees by twining around its  branches,

“It will deform branches and it will break branches.  Fungi and other disease agents can get in there.  So  it has multiple ways of weakening the tree, ” Marx said. 

Marx says Oriental Bittersweet vines are woody and can weigh more than the tree itself. and they are the only known plant that actually kills its host.

“We are here in front of a nice big example of a bittersweet and when they get that big their weight gets large and in a storm you can have large branches breaking off or the entire trunk, ” Marx said. 

The report looked at trees from Long Island Sound to northern New Hampshire and along the Canadian border.  Scientists found that between 2008 and 2011 the vine killed more trees than any other climbing vine. Oriental Bittersweet attacks  trees growing on the forest’s edge first, then moves inward, destroying the forest’s canopy in the process. Scientists have no natural way to stop the vine from spreading. Oriental Bittersweet must be physically removed and the stump killed with a herbicide. The report found that beavers are the first cause of floodplain tree mortality.