by Steve Reinbrecht
There is a forest stretching through my neighborhood, all one kind of tree, an invader from East Asia that pushes out the local plants.
Bradford pear trees [Pyrus calleryana] are pretty. They brighten up our neighborhood this time of year. Also known as Callery pears, the tree is native to East Asia. Developers installed them among homes and businesses all over the United States.
But now, experts warn against planting them, mostly because they break catastrophically if not pruned when they are small. And they grow happily everywhere, spread by birds, especially starlings [another invasive] and robins, a native though opportunistic sort of bird.
On Saturday, robins, swarmed the thicket of pears in bloom south of the Wilson West Middle School. The trees are invading the area, some of it set aside as educational open space.
A huge swath of the trees winds along the Little Cacoosing Creek and then across Green Valley Road and along a power-line easement. The trees are thick and dominant.
They were full of robins Saturday.
But I wonder if other native birds and pollinators feel at home in the foreign species.
Bradford pear forms dense thickets that push out other plants, including native species, that can’t tolerate its deep shade or compete with it for water, soil and space, the National Park Service says.
Its success as an invader results from three things, the service says. It can produce copious amounts of seed that is dispersed by birds and possibly small mammals. Its seedlings grow rapidly in disturbed areas. And it lacks natural controls like insects and diseases, with the exception of fire blight.
Identifying these species when they are first spreading could reduce the eventual high cost of their control and eradication.
