Lots of backlinks from Google Plus

Selected answers from the Dumb SEO Questions Facebook & G+ community.

• 
  Ben Baligad: Last January, I started a Google Plus community. It turned out that my invitations to that community showed up as posts on my profile. The community has links to my website.
  
  I did not really count how many I invited to the community. I would say, a little more than 1,000. I keep track of links pointing to my website through Google Webmaster Tools. Around the time invited the 1,000, there were an extra 1,000 links pointing to my site, all from Google Plus. ;
  
  That made think that Google Plus links are dofollow links. Was this a strange coincidence or are there certain situations when Google Plus links are dofollow? ;
• 
  Michael Cloke: Question: did you see an improvement in the serps after all these posts?
• 
  Ben Baligad: For a while, a little. But, I have read that it may take months before links kick in. It never rose beyond that little.
  
  Right now, I am below from where I started from. I think a Panda might have my site.  ;There was a big drop on my impressions about a week ago. I suspect  ;it is from my Google Plus activities because that is mostly what I do. ;