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Comment by Helmut10001 | Hacker News Reader

Note that in Germany and Switzerland, Asclepias syriaca (Milkweed) is considered invasive, with a negative impact on biodiversity. Only plant in North America!

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How long from a species being invasive to it being considered native?

Here in Norway it's mostly spruce, pine and birch all over. Surely they were invasive at some point.

The black locust (Robinia pseudoacacia) [1] was brought to Europe about 400 years ago [2]. It is considered currently crucial for biodiversity, especially for insects, bees etc. due to early bloom in spring. It also adds atmospheric nitrogen through root bacteria and improves bad (sandy and eroded) soil. It is one of the most important hard woods in Europe these days for outside constructions, due to its resistance against rot, without requiring impregnation.

This is not common, however. Most invasive species shift the balance in local ecosystems and the common outcome is a lesser diversity of species, with more aggressive ones winning. Natural biodiversity drift does not have the same impact, as it occurs more slowly than human propagation of species.

[1]: https://en.wikipedia.org/wiki/Robinia_pseudoacacia

[2]: https://de.wikipedia.org/wiki/Gew%C3%B6hnliche_Robinie#Einf%...

It is also taking over all the native trees. At least in France. There are entire forests (non commercial) of diverse trees that are now only black locust.

Which is great because being an awesome tree for bowmaking, nobody cares if you harvest a few straight stave: On the contrary people will say "Good, you're removing these" :-)

Plus they give excellent liquid yellow honey and you can make yummy perfumed donuts with their flowers.

But yeah, it's a pain to get rid of: even if cut, they will regrow nearly endlessly and their thorns are so pointy and durable that they routinely kill tires...

Forgot to add, here is the source for the information [1]

[1]: https://de.wikipedia.org/wiki/Gew%C3%B6hnliche_Seidenpflanze

In the whole EU, not just Germany. Planting, trading or importing milkweed is banned.

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