It is a perenial flower, either being spread via seeds but it can also spread by root noduals and stem fragments. With so many different ways it can reproduce, it's no wonder plants like these take a hold in forest ecosystem.
There are many ways in which you could try and control these plants;
- You could do it all manually by taking out the root systems by hand. But this would be fruitless because the root systems on these types of plants can be huge.
- You could keep cutting them back. But if this is done at the wrong time of the year you could actually make things much worse. It is also it was very labour intensive.
- Or you could Spray the plants with chemicals which can be done easily and will take out the plant and the root. But you are introducing chemicals into a ecosystem which is never really a viable alternative can never be very good. Even if it says so on the label.
The best approach in my mind is using all these methods. Well not all, i think in every situation, chemicals can never be the answer.