Originally Posted by tonygreek
Assuming I'm looking at the correct site, their comment system does display recent comments on each page, via the right sidebar. All of their outbound links show as nofollows, so who knows. I still think the backlinks are as a result of this. If you want, shoot me a pm and I'll take a look at them. My guess is you'll see them drop off your report sooner rather than later.
Many comment systems have the field for your web site. Whether they publish it or not is usually stated.
A Blog Roll is a list of related/interesting sites that is usually in one of the sidebars.
Someone just posted on a site or blog about the tallest maple I found.
I was trying to find other references to tallest + maple to see what else others might have found in the past, and the search included the site where the write-up was done on my discovery. There were dozens, at least, if not more, back links, even though it's really on one page.
So I'm sure Google and other search engines have figured out how to deal with that kind of thing so they don't credit the site more than needed.