Ornamental pears are invasive, and cross pollinate with local pears. They might be pretty in the spring, and ironically an apiary near me just planted a bunch of them since they flower earliest in the year–for the bees’ early-spring food–but the trees are slowly taking over from mid-sized native trees like dogwoods and redbuds in wild forests.
Here is an article on ornamental pears, “The Curse of the Bradford Pear.” Quote:
And, make no mistake about this. That solitary Bradford pear growing in your yard is what caused this problem. Your one tree has spawned hundreds of evil progeny. If you don’t believe that, just take a little ride, and notice all the white flowering trees blooming these days. The closer they are to “ornamental” Bradford pear trees, the thicker they are.
If you want to save the world, cut down your Bradford pear trees. I could not be more serious about this.
He even goes on to say that the way you can tell a good Garden Center from a bad one is whether or not they sell ornamental pear trees.
Read the rest here. https://www.greenvilleonline.com/story/life/2016/03/21/curse-bradford-pe…
About the only good thing I can say about them is that urban guerrilla gardeners can graft actual fruit branches on them.