Invasive species
Frangula alnus was probably introduced to North America about 200 years ago, and in Canada about 100 years ago. It was planted for hedgerows,
forestry plantings, and wildlife habitat, but has become an invasive species, invading forests in the northeastern United States and wetlands and
moist forest in the Midwestern United States.[13][14][15] It is predicted to continue to expand its North American range with time.[13] Its
invasiveness is assisted by its high adaptability and pollution tolerance.[16]
It invades forests and grows in the understory in spots with a lot of light. These areas, usually where a tree has fallen, normally allow locally
native tree seedlings to grow and eventually fill in the gap in the canopy. But when Frangula alnus invades and grows in these locations, its dense
canopy prevents light from reaching the ground and therefore prevents other seedlings from growing.[16] It tends to grow more densely and with larger
individuals in lower topographical areas with moist, fertile soils, and is very problematic for land managers.
|