In what ways is buckthorn harmful?

I spent 10-15 hours a week in various locations of still-wooded Chicago (and now nearby Lincolnwood) cutting down buckthorn. Some people have taken me to task for it ("Just let it be, let nature take it's course, etc.). So I thought I would share this excellent, concise sum up of the damage that can be wrought by buckthorn.

And if anyone lives on the north side of Chicago and would like to help out, there is both "heavy" work (cutting large trees and dragging them around) and now lots of "light" work (clipping the new growth from the stumps from last year's cutting - I don't use poison). 

It's great exercise and without a doubt you will be helping rescue native trees and ensure that the next generation of those trees will survive and thrive!

From The Landscape Guys

Buckthorn should be on America's "Most Wanted" list, with its picture hanging up in every US Post Office! Here are a few of the dangers of Buckthorn:

a) Buckthorn squeezes out native plants for nutrients, sunlight, and moisture. It literally chokes out surrounding healthy trees and makes it impossible for any new growth to take root under its cancerous canopy of dense vegetation.

b) Buckthorn degrades wildlife habitats and alters the natural food chain in and growth of an otherwise healthy forest. It disrupts the whole natural balance of the ecosystem.

c) Buckthorn can host pests like Crown Rust Fungus and Soybean Aphids. Crown Rust can devastate oat crops and a wide variety of other grasses. Soybean Aphids can have a devastating effect on the yield of soybean crops. Without buckthorn as host, these pests couldn't survive to blight crops.

d) Buckthorn contributes to erosion by overshadowing plants that grow on the forest floor, causing them to die and causing the soil to lose the integrity and structure created by such plants.

e) Buckthorn lacks "natural controls" like insects or diseases that would curb its growth. A Buckthorn-infested forest is too dense to walk through, and the thorns of Common Buckthorn will leave you bloodied.

f) Buckthorn attracts many species of birds (especially robins and cedar waxwings) that eat the berries and spread the seeds through excrement. Not only are the birds attracted to the plentiful berries, but because the buckthorn berries have a diuretic and cathartic effect, the birds pass the seeds very quickly to the surrounding areas of the forest. This makes Buckthorn spread even more widely and rapidly, making it harder for us to control and contain.