There is a vast difference between plants which are able to naturalize in different settings and plants which upset the balance of ecosystems and cause economic and/or ecological calamity. One example of the latter is chickweed, which can invade farmland, wreaking havoc on a farmer's ability to produce grain crops. Another example is melaleuca or tea tree, which has invaded Florida wetlands and has caused intense displacement of native species and disruption of economic activities in those areas. Mitigating and controlling invasions of this type cost American taxpayers billions of dollars and disrupt complex systems which we rely on for a variety of invaluable and necessary resources.
I have not found any examples of paulownia being included in this group of plants which show destructively invasive potential. In fact, I have only found a great deal of research showing that paulownia participates well in existing forests and increases forest resilience. Paulownia trees recover quickly from destructive events and provide shelter for wildlife including sun and wind shelter for emerging seedlings. Paulownia trees also grow well at forest boundaries, increasing biodiversity and reducing encroachment on forest environments while providing emergency forage for ruminants when they are most likely to need it.
Due to the low energy content of the tiny seeds which paulownia trees produce prolifically, it is incapable of competing with any other plants including grasses, and so is unlikely to be able to establish itself anywhere that there is existing growth of any kind. Once it is established, a paulownia tree is not likely to grow as quickly as it would in plantations where they are fertilized and where competing growth is often discouraged mechanically or chemically. Additionally, paulownia trees do not produce seeds for 7-10 years after they begin growing, which is approximately when cultivated trees are ready to be harvested for lumber. All these factors serve to reduce the potential for destructive invasiveness of cultivated paulownia.
States where it is regulated include:
- South Carolina
Well, it's there America, growing in many of our managed and unmanaged forests and parks, if we really cared about it's long-term potential to overpopulate and dominate these eco-systems, then we would be doing more research about it's growth habits because at this point, eradication would involve a pretty intense effort and the potential economic and ecological benefits of paulownia are massive.
- USDA information about invasiveness of paulownia
- New Zealand forestry manual about Paulownia
- environmentalist rant about paulownia
- another environmental type article in NY Times
- agroforestry information
- ebook about paulownia seed and seedling dispersion
- book about apple genetic diversity
- woodworking quality of paulownia lumber
- dissertation about paulownia invasion by A. Christina W. Longbrake
- alternative farming systems information center
- New Zealand paulownia farming information booklet
- tree crops for marginal land - Tennessee