>>5020231
>>5020390
One of the primary ways that invasives take hold is actually disturbed areas such as road berms. In a mature forest, every niche is filled and there isn't any room for something like knotweed or purple loosestrife to take root but in areas that are regularly mowed, tilled or otherwise disturbed the fastest growing plants are the ones that take hold and that's often invasives which can tolerate subpar growing conditions such as highly contaminated roadside soil.