Invasive Norway Maples Threatens LI Forests

Exotic Norway maples invading a forest in Queens. Note the dense shade & lack of ground vegetation.

From the Long Island Botanical Society's newsletter, summer 2005 - summary of Wei Fang's research & article:

Norway maple (Acer platanoides)was first introduced to this country in 1760s & quickly gained popularity as an ornamental species. By the late 1990s, it was considered to the be the #1 planted street tree in the U.S. In recent years, Norway maple has expanded from its ornamental realm into sections of parks & nature preserves. Once there, it forms single species (monospecific) stands & inhibits groundcover establishment.

Wei Fang's three year study showed that not only is Norway maple expanding its reach within the forests of Long Island, but as the number of Norway maples increases, so too does the number of other exotics, such as Japanese honeysuckle (Lonicera japonica) & winged burning bush (Euonymus alatus). Furthermore, limits the availability of resources to other plants - its larger leaves exclude other vegetation from receiving sunlight & it changes soil chemistry resulting in higher nitrogen loss.

Here is the abstract.