[Tagging] wetland=bog, why only "receive their water and nutrients from rainfall"?

[Christoph Hormann]

On Sunday 24 January 2016, Andy Townsend wrote:
> What does "fen" means to you?
>
> I've a fairly good idea what I think it means, and I'd never or
> almost never tag it as a natural feature (though it may have a name,
> and the natural features within it may have names).

As a non-native English speaker i do not have a genuine understanding of 
the word fen but in terms of wetland types i consider fens peat 
producing wetlands with lower acidity and higher levels of nutrients 
and therefore hosting more diverse plant communities than bogs.  There 
are boundary cases of course.

> Could you come up with some examples of things that are currently
> tagged as bogs but shouldn't be, or aren't tagged as fens but should
> be (in the UK and Ireland would be helpful to me, as that's what I'm
> going to be most familiar with, but obviously other places will be
> helpful to other people).

For the UK/Ireland this is difficult without local knowledge.  Due to 
the climate and geology blanket bogs are very widespread there and the 
presence of a stream in the area for example does not necessarily mean 
it feeds the wetland - it can still be primarily fed by rainfall.

Here in Germany with a drier, more continental climate you can pretty 
much rule out any wetland at the shore of a larger lake or next to a 
larger river to be a bog.  Like: 

http://www.openstreetmap.org/#map=15/51.0768/12.4432
http://www.openstreetmap.org/#map=15/51.0303/12.4669
http://www.openstreetmap.org/#map=14/53.9642/13.1271
http://www.openstreetmap.org/#map=17/54.00570/12.12454
http://www.openstreetmap.org/#map=14/48.1004/11.1292

And if you look at 

http://taginfo.openstreetmap.org/tags/wetland=bog#map

you can also see bogs mapped in regions (like Tunesia) where climate 
would not allow the formation of bogs.

-- 
Christoph Hormann
http://www.imagico.de/