Yesterday I was out on a friends' property in West Virginia, on a New Years' Day hike, which happened to take us past a patch of Tree of Heaven that they had eradicated 2 years ago.
Today I surfed over to plants.usda.gov to find they had picked "Tree of Heaven" as the plant of the week!
Ailanthus altissima is an invasive exotic, particularly in the eastern states. Originally from China, it was introduced in Philadelphia in 1784. It sprouts from the roots and is a prolific seed producer that grows well on disturbed lands, which is where we found it on our friends' property... on the dam that created their pond.
Time will tell if our attempts to blink out one seed source will succeed. The trees that were treated have fallen down, but we already see signs of sprouting, and the water from the pond overflow could carry the seeds downstream of the pond.
In any attempt at stewardship it's easy to be discouraged, worry that we won't make a big enough difference. Like every problem of the commons, maybe we need to measure success by the accumulation of all our efforts, not the individual impact?