> Yes, Singapore is great for that. But to be fair with the other cities, it’s very hard _not_ to have abundant vegetation in tropical rainforest climate. Everything grows rapidly and stops at nothing in its way.

Eh, have a look at other tropical cities like Johor Bahru or Jakarta or Kuala Lumpur and you can see that it's very much possible to have way less greenery than Singapore.

The recent trouble with the Borkenkäfer was just a consequence of monoculture. Germany doesn't struggle with keeping forests alive: it's normal at any one time for individual trees in forests to die. Decaying dead wood is important for the ecosystems.

Less than Singapore for sure. Less than European cities, I’m not so sure. I don’t have the numbers but if you do an image search of Jakarta (probably one of the worst vegetation-wise and boasting a population of a quarter of Germany) it still has trees in every picture and many more than let’s say Frankfurt or Madrid. The latter has many photos without a single tree.

79% of all German trees are sick. Monocultures and beetles play a role but the problem is much bigger than that: https://www.bmleh.de/DE/themen/wald/wald-in-deutschland/wald...

> The recent trouble with the Borkenkäfer was just a consequence of monoculture.

Even worse. It was monoculture of trees that aren't even native to the climate zone. The trees were imported from Scandinavia for their superior lumber quality, and were on edge even without the added stress from droughts and heat waves.