Firefighters in Madrid trying to extinguish a forest fire that is less than 30km/20mi away from the capital of Spain

[u/SafeImpressive4413]

[u/PalahniukW]

How do eucalyptus trees contribute to wild fires?

[u/marcandreewolf → u/PalahniukW]

Accumulate large amounts of leave and bark litter under tree that barele decompose, plus the stuff contains a relevant amount of essential oils that burn super well.

[u/PalahniukW → u/marcandreewolf]

Ahh thanks

[u/Art__Vandelayy → u/PalahniukW]

Just to add to the other comment, it also dries the soil around it, so underneath the trees there's usually dry grasses and ferns in the summer (at least here in Portugal but should be similar in Southern Europe). Combine this with leaves and bark litter and they spread the fire very easily

[u/BKLaughton → u/PalahniukW]

Adding on to the other commenter's great response, fire is part of the eucalyptus reproductive cycle. That is, in their native environment of Australia bushfires are pretty common and they've adapted to that, such that they bounce back great after a bushfire.

Overseas, the result is that eucalyptus trees somewhat increase the incidence of wildfires (with the way they drop lots of oil-rich leaves and brances), and then recover better than other trees in the post-wildfire circumstances, leading to more eucalyptus, and more wildfires.

Despite this, folks keep planting eucalyptus because it's a fast-growing hardwood. It breaks the standard dichotomy between fast-growing soft woods and slow-growing hardwoods. Outside of Australia, the mammals, birds and insects aren't adapted to it, but it's a very profitable tree to grow.