Why are all the trees in Berlin, DE numbered?

I don't have a definitive answer, but some clues: "

Great story! Two comments on trees in Berlin: All of the trees are numbered with little metal tags. Small children (and foreigners) are sometimes told that this is to identify where the trees are to be returned to when they run away...

A Berliner once told me that trees (and the Tiergarten and other parks) are hugely symbolically important in Berlin, since in 1945 and 46, almost all of them were chopped down for firewood, and when the wall went up, it made it very difficult for families to venture outside into the countryside. West-Berlin had to bring the countryside into the city and planted more trees per capita than most German cities to offset the hardship."

http://andrewhammel.typepad.com/german_joys/2007/04/due_process_for.html

Well, if you have a court-case about a tree, it might be easier if you can identify it. Same probably goes for the gardening and history of these trees. Just a guess :)

Btw.: Why do you assume that it has something to do with the Holocaust?

Not one thing to do with the Holocaust. Honestly, as a Jewish German-American with families in both countries I am ceaselessly amazed how much Germany, Germans, and German activities seem to be reduced to the darkest, yet very definitely not sole, period in German history.

But to answer your question. Berlin trees are listed in a Senate (which is the Berlin version of a state government) library file called the "Baum Kataster". Tree ownership in Berlin is a governmental mandate and as such the government is required to assess, catalogue, and maintain the tree population in the city. Numbers are used:

- first, to assign work orders and post requests for bids for private sector services.

- to ascertain and properly file claims against the owner (that'd be the Berlin Senate) for both property damage and personal injury as a result of tree related incidents

- to discourage theft,

- and to fine those who damage trees.

Simple as that. It's bureaucracy, good, old fashioned, Prussian, bureaucracy where things need a number to be considered property.

They’re also doing the labelling thing in Hong Kong. Very ugly labels, very stupid idea.