Should I put rel=publisher on UGC?

[MarloSchneider]

My website has a main section that we call expert content and write for. We also have a community subdomain which is all user generated.

We are a pretty big brand and I am wondering should the rel publisher tag just be for the www expert content, or should we also use it on the community UGC even though we don't directly write that?

[RobertFisher]

Spencer, a most excellent question IMO.

I am going to stick my neck out here and say use it on both. It took some thinking and digging for me to wrap my head around it, but I think I have it:

You should only use rel=pub on one page of the site. Given that, you use it on the one that is your brand or which has the most traffic, gets lots of plus ones, etc. But, you said this:  We also have a community subdomain...

I think the subdomain should be treated as its own site and let it also have rel=pub to the G+ of your main site. The individuals who write, whether for UGC or your experts writing will be rel=author for their pieces.

By doing it this way you can aggregate the plus ones to your G+ from all which gives your site a better profile in the eyes of the Google. This opens a lot of doors for you (at G's choice obviously.  Now, I am certainly open to being wrong, but if you think about it for a moment it makes sense in this way: If your firm owns multiple sites (we are a marketing firm and we own a few properties ourselves outside of the main site) but your brand is what owns them, then you can be the pub of all. Again, the individuals writing will be the rel=author. 
I look forward to more comments. Most excellent question for forcing us to think.

[RobMay]

I would surely (and only) use the rel-publisher field on the professional writer content and tie that into the Google+ profiles to have your listings and content stand out in SERP results, but would stay away from trying to get that tied together in the UGC section. Just my 2 cents, but without regular postings by UGC and tying that into the Google+ profiles of those writers who contribute, I don't think you would get the value back.

If these writers in the UGC are frequent, invite them to contribute to the PRO section of the site as 'guest' bloggers or writers. Just some suggestions I would follow myself Hope it helps!

Cheers!